.ragatouille/colbert/indexes/cbseclass10index/collection.json

[
  "Improvement In Food Resources.txt\nClass IX  Science    1 \nRevision Notes \nClass 9 Science \nChapter 12 - Improvements in Food Resources \nAll living species require food to survive. Plants and animals provide us with food. \nFood  demand  has risen  dramatically  as the world's  population  has grown.  It is critical \nthat we expand  food production  without  harming  our ecosystem  or disrupting  the \ndelicate  balances  that keep  it in check.  As a result,  sustainable  agricultural  and \nanimal husbandry practises are required. \n1.Improvement in crop yields :\nFor their growth and completion of their life cycle, different crops require different\nclimatic conditions, temperatures, and photoperiods. Some crops are planted during\nthe rainy season, known as kharif crops, which last from June through October.\nPaddy, soya bean, maize, cotton, green gramme, and black gramme are among the\nKharif crops. Rabi crops are planted from November through April during the winter",
  "Improvement In Food Resources.txt\nPaddy, soya bean, maize, cotton, green gramme, and black gramme are among the\nKharif crops. Rabi crops are planted from November through April during the winter\nseason. Wheat, gramme, peas, and linseed are among the Rabi crops. Crop variety\nimprovement, crop production improvement, and crop protection management are\nthe three key groups of efforts for increasing crop y ields.\n2.Crop variety improvement:\nCrop variety enhancement can be accomplished through the selecting process.\nHigher yield, increased quality, biotic and abiotic resistance, change in maturity\nduration, wider adaptability, desirable agronomic traits, and so on are some of the\nfactors that lead to variety improvement. A cross between two different varieties,\nknown as inter -varietal crossing, or between two different genera, known as inter -\ngeneric crossing, or between two different species, known as inter -specific crossing,\nresults in hybridi zation. Crop output can also be boosted by inserting beneficial",
  "Improvement In Food Resources.txt\ngeneric crossing, or between two different species, known as inter -specific crossing,\nresults in hybridi zation. Crop output can also be boosted by inserting beneficial\ngenes into the crop plant. As a result, genetically engineered crops are produced.\n3.Crop production management :\nIt refers to the safeguarding of crops that are either growing or have been harv ested.\nCrop output can be improved by nutrient management, irrigation, and cropping\npatterns.\nAgricultural practises refer to a variety of actions carried out by farmers in order to\nproduce crops. Agricultural methods include the following activities:\n\u27a2 Preparing the soil\n\u27a2 Sowing\n\u27a2 Adding fertilisers and manure",
  "Improvement In Food Resources.txt\nClass IX  Science     2 \n \n \n\u27a2 Irrigation  \n\u27a2 Defending against weeds  \n\u27a2 Harvesting  \n\u27a2 Storage  \n \nThe overall strength of the end result \u2014 the crops that are growing \u2014 will be \ndetermined by the quality of the soil, seeds, and planting procedures. Corn benefits \nfrom the use of strong hybrid seed that can withstand harsh circumstances and \nmaximise yields. Although seed science has advanced significantly, there are still \napproaches and methods that can be used to improve farm efficiency.  \nThese nutrien ts can be added to the soil in the form of manure and fertilisers.",
  "Improvement In Food Resources.txt\n4. Nutrient management:  \nAir, water, and soil are all sources of nutrients for plants. Macronutrients and \nmicronutrients are the two types of nutrients found in plants. Carbon and oxygen are \nboth supplied by air. Hydrogen and oxygen are both found in water. Plants get the \nremainin g 13 nutrients from the soil. Plants' physiological activities, such as \nreproduction, growth, and disease susceptibility, are affected by nutritional \ndeficiencies. The soil can be improved by adding these nutrients in the form of \nmanure and fertilisers to increase output.",
  "Improvement In Food Resources.txt\n5. Manure:  \nManure is created naturally when animal excreta and plant waste decompose. It \ncontains organic matter, which promotes water retention in sandy soils and avoids \nwater logging in clayey soils. Compost is made by decomposing farm was te, \nvegetable waste, household garbage, and sewage waste in pits using the composting \nprocess. Vermicompost is made by utilising earthworms to speed up the \ndecomposition of plant and animal waste through the vermi -composting process. \nPlowing nitrogen and p hosphorus -rich plants into the soil before sowing seeds \nprovides green manure to the plants.",
  "Improvement In Food Resources.txt\n6. Fertilizers : \nFertilizers provide nitrogen, phosphorus and potassium to plants. They're utilised to \npromote healthy plant growth by ensuring good vegetative growth. Fertilizers play \na role in high -cost farming's better yields. Organic farming is a farming technique \nthat uses organic manures, recycled farm wastes, and bio agents with little or no \nusage of chemicals such as fertilisers, herbicides, insecticides, and other pesticides.  \n \n7. Irrigation:  \nDuring the growth season, ensuring that the crops receive water at the approp riate \ntimes can boost the predicted yields of any crop. Irrigation is carried out using both  \n \nClass IX  Science     3 \n \n \nold and modern ways. Depending on the types of water resources available, \nirrigation systems are used to supply water to agricultural regions. Rivers, canals, \npond s, lakes, tanks, dams, and groundwater are all examples of ground water \nsources.",
  "Improvement In Food Resources.txt\n8. Cropping pattern:  \nMixed cropping, intercropping, and crop rotation are examples of different cropping \npatterns. Growing two or more crops on the same piece of land is known a s mixed \ncropping. Wheat and gramme, for example, or peanut and sunflower. Intercropping \nis the practise of growing two or more crops on the same field at the same time, with \ncertain rows of one crop alternating with rows of the other, such as soya bean and  \nmaize. Crop rotation is the practise of cultivating two or three different crops on the \nsame piece of land over the course of a year. Cereals and legumes, for example.",
  "Improvement In Food Resources.txt\n9. Crop protection management:  \nWeeds are undesired plants that compete for food, space, a nd light with crop plants, \nreducing crop development. Herbicides or mechanical weed removal can be used to \nget rid of weeds. e.g. Xanthium.  \nPathogens such as bacteria, fungus, and viruses cause diseases in plants. Herbicides, \nfungicides, insecticides, and other pesticides can be used to control pathogens.  \nWeed management can also be achieved by preventative measures such as good seed \nbed preparation, timely crop sowing, intercropping, and crop rotation.",
  "Improvement In Food Resources.txt\n10.  Storage of grains:  \nAbiotic factors such as insects, rodents, fungi, mites, and bacteria cause agricultural \nstorage losses. Crops are also harmed by abiotic factors such as insufficient moisture \nand temperature in the storage area. These factors can be controlled through proper \nwarehouse treatment and manage ment.  \nBefore grains are kept for future use, preventive and control procedures are taken. \nThey include thorough cleaning of the product prior to storage, proper drying of the \nproduce in the sun and subsequently in the shade, and pesticide fumigation.  \n \n11.  Animal Husbandry:  \nAnimal husbandry refers to the scientific management of livestock animals. It covers \na wide range of topics, including feeding, breeding, and disease control. Cattle, goat, \nsheep, poultry, and fish farming are examples of animal -based farmin g.",
  "Improvement In Food Resources.txt\n12.  Cattle farming:  \nCattle farming serves two purposes: milk production and draught labour for \nagricultural tasks including tiling, irrigation, and hauling. Draught animals are  \n \nClass IX  Science     4",
  "Improvement In Food Resources.txt\nutilised for farm labour while milk animals provide milk. Bos Indicus, or cows, and \nBosbubalis, or buffaloes, are the two most common Indian cattle species.  \nCleaning, sheltering, and feeding are all part of cow management. Cleaning entails \nwashing on a regular basis to remove dirt and loose hair. Shelter facilities include \nwell-ventilated roof sheds tha t keep cattle dry, warm, and protected from the sun. \nRoughage feed, which is mostly fibre, and concentrate feed, which is low in fibre \nbut high in proteins and other nutrients, are two types of animal feed.  \nA variety of diseases affect cattle. In addition to causing death, the illnesses limit \nmilk output. External and internal parasites both cause disease in cattle. External \nparasites are parasites that dwell on the surface of the skin and cause skin disorders. \nInternal parasites wreak havoc on the stomach and intestines. Farm animals are \nvaccinated against a variety of viral and bacterial infections.",
  "Improvement In Food Resources.txt\n13.  Poultry farming:  \nPoultry farming is the activity of keeping chickens for the purpose of producing eggs \nand meat. Broilers are used to produce meat and layers  are used to produce eggs. In \norder to generate new types with desirable features, cross -breeding is prevalent in \npoultry. For example, the Indian breed Aseel has been crossed with the foreign breed \nLeghorn.  \nCross -breeding is a technique for producing offs pring with desirable characteristics. \nDwarf broilers that may be utilised as meat in a short amount of time, a higher \nnumber and higher quality of chicks, and resistance to high temperatures throughout \nthe summer are all desired qualities.  \nGood management methods are essential for good poultry bird production. These \ninclude temperature and hygienic conditions in housing and chicken feed, as well as \ndisease and pest prevention and management.",
  "Improvement In Food Resources.txt\n14.  Fish production:  \nTinned real fish, as well as shellfish such as prawns and mollusks, are all produced. \nFish can be obtained in two ways. The first is catch fishing, which is based on natural \nresources. Fish farming, often known as culture fishery, is another option.  \n \n15.  Marine fisheries:  \nPopular marine fish include mullets, pomfret, mackerel, tuna, sardines, pearl spots, \nshellfish like prawns, mussels, and oysters, and Bombay duck. A number of high -\nvalue marine fish are also cultivated in seawater. Sea weeds like guso, elkhorn sea \nmoss, Gr acilaria, Wakame, etc are all examples. Oysters are also cultivated for their \npearls.  \nAs marine fish stocks become lower, only culture fisheries, also known as \nmariculture, can meet the need for additional fish.  \n  \n \nClass IX  Science     5",
  "Improvement In Food Resources.txt\nClass IX  Science     5 \n \n \n16.  Inland fisheries:  \nFish culture is occasion ally done in conjunction with a rice crop, allowing fish to \ngrow in the paddy field's water. In a composite fish culture system, more extensive \nfish farming is possible. In this arrangement, a single fishpond contains a mix of five \nor six different fish sp ecies.  \nCatlas feed on the surface, Rohus feed in the middle of the pond, Mrigals and \ncommon carps feed on the bottom, and grass carps graze on the pond's weeds.  \nA hormone stimulation strategy is used to solve the problem of poor seed quality in \nfish farmin g. This has assured that pure fish seed is available in the amounts \nrequired.",
  "Improvement In Food Resources.txt\n17.  Bee keeping:  \nBeekeeping, also known as apiculture, is the activity of keeping honey bee colonies \nin hives. It doesn't require a lot of money. Apiaries, often known as bee farms , are \nused to produce honey for commercial purposes. Beehives produce wax, which is \nutilised in a variety of therapeutic formulations in addition to honey.  \nCommercial honey is produced by Apis cercana  indica (Indian bee), Apis dorsata  \n(Rock bee), Apis florea  (little bee), and Apis mellifera  (Italian bee).  \nThe pasturage or flowers available to bees for nectar and pollen gathering define the \nworth or quality of honey, and the type of flowers available determines the honey's \ntaste.",
  "Sound.txt\n   1  \n \n  \nRevision Notes for Class 9 Science  \nChapter 11 \u2013 Sound  \n \nIntroduction  \n\u2022 You've discovered that sound is a type of energy. Vibrations cause it to happen. \nLongitudinal waves are sound waves. Because they are elastic waves, they must be \ntransmitted through a material medium. They are not capable of being communicated \nin a vacuum.  They can move through solids, liquids, and gases. In solids, their velocity \nis greatest, whereas in gases, it is lowest.  \n\u2022 In our daily lives, we hear a variety of sounds: pleasant sounds termed musical sounds, \nunpleasant noises called noise, loud sounds, high pitched sounds, and so on.  \n\u2022 In this chapter, we'll look at the differences between pleasant and unpleasant sound, as \nwell as the elements that influence loudness, pitch, and other aspects of sound.",
  "Sound.txt\nSound as a Wave  \n\u2022 To us, a ringing bell, a thunderclap, laughter, and rock music are all very different \nnoises. However, because all sounds are waves, they are all the same. Let's look at how \nwave qualities can be used to apply to sound.  \n\u2022 Sound is a kind of energy that is sent as waves and received by our ears. Our vocal \ncords vibrate as we talk. When we play a guitar, the spring moves back and forth, \nproducing sound. The vibrations of a tuning fork also make sound. As a result of its \nvibra tions, a body makes sound. Sound waves can't travel in vacuum, hence they need \nto travel through a material medium.   \n \n \n    2  \n \n  \n\u2022 You can hear because sound waves cause your eardrums to vibrate when they reach \nyour ears. The vibrations are then relayed to your brain by nerves. The messages are \ntranslated into sound by the brain.  \n \nPropagation of Sound  \n \n \n \n \n \n    3",
  "Sound.txt\nPropagation of sound waves in air from a tuning fork:  \n\u2022 A longitudinal wave is a wave motion in which the particles of the medium oscillate \nabout their mean positions in the wave's propagation direction.  \n\u2022 Longitudinal waves are the most common type of sound wave. Let's look at how sound \nwaves travel. Take a tuning fork and shake it while focusing on one of the prongs, say \nprong A. The tuning fork's typical position and the initial state of air particles are  \ndepicted in the diagram (a). As prong A advances to the right, air particles near it are \ncompressed, generating a compression as depicted in fig (b). This compression \nproceeds forward as a disturbance due to vibrating air layers.  \n\u2022 The pressure on prong A's right lessens as it returns to its previous position, generating \na rarefaction. As a disturbance, this rarefaction travels forward like compression. As the \ntuning fork continues to vibrate, waves of alternated compressions and rar efactions",
  "Sound.txt\na rarefaction. As a disturbance, this rarefaction travels forward like compression. As the \ntuning fork continues to vibrate, waves of alternated compressions and rar efactions \npropagate through the air, as shown in fig (d). Because sound waves travel in the same \ndirection as air particles, they are classed as longitudinal waves. Longitudinal waves \ntake the shape of compressions and rarefactions as they travel.",
  "Sound.txt\nSound Needs a Medium to Travel  \nSome vibrating body is always the source of sound. The vibrations of the source may be so \nsmall or so enormous that they are impossible to detect in some situations. Tuning forks, \ndrums, bells, guitar strings, and other instruments produce this type of vib ration. The \nvibrations of the vocal cords give rise to the human voice, and the vibrations of the air columns \ngive rise to musical instrument sound. Sound travels in the form of a longitudinal wave that \nneeds to be propagated through a material medium.  \n \n \n  \n \n \n    4  \n \n  \nExperiment to show that sound waves (mechanical waves) require a material medium \nfor its propagation:",
  "Sound.txt\n   4  \n \n  \nExperiment to show that sound waves (mechanical waves) require a material medium \nfor its propagation:  \n \n \nElectric bell suspended inside an airtight glass bell jar  \nA vacuum pump is attached to an electric bell hung inside an airtight glass bell jar. The sound \nis heard as the electric bell circuit is finished. After the air in the bell jar is gently withdrawn \nwith a vacuum pump, the strength of the sound gradually dec reases until no sound is heard \nwhen all of the air is removed. We would observe the hammer continually striking the gong. \nThis clearly demonstrates that sound propagation requires the presence of a substance. Not \nonly can sound travel through gases, but it  can also travel through solids and liquids. Some \nmaterials, such as air, water, and iron, are good at transmitting sound energy from one location \nto another. Materials like blankets and thick curtains, on the other hand, absorb the majority \nof sound energ y.",
  "Sound.txt\n\u2022 Basic Terms Connected to Waves:  \nWavelength, Amplitude, Frequency, and Wave Velocity are the four key terms in the study of \nwaves.  \n \n \n \n    5  \n \n  \nThe distance between two consecutive spots on a wave that are in the same phase is known as \nthe wavelength. (The same phase denotes the same vibrational state.)  \n The largest displacement of a particle from its mean position is called amplitude. The number \nof periodic oscillations completed in one second is known as frequency. The frequency  f = \n1/T, where 'T' is the time it takes for one oscillation to complete. The hertz  Hz is the unit of \nmeasurement. The wave velocity 'v' is the rate at which energy propagates through a medium.",
  "Sound.txt\nSound wave  \nThe product of the wavelength and frequency gives us the wave velocity because wavelength \nis the distance travelled during one oscillation and frequency is the number of oscillations per \nsecond.  \nDistance travelled in  1 s =  number of waves in one -second x wavelength   \nWave velocity = Frequency  \u00d7 Wavelength   \nor, \nv = f (x)  \n \n \n \n    6",
  "Sound.txt\n   6  \n \n  \nSpeed of Sound:   \nAlthough both occur at the same time, the flash of lightning caused by cloud interaction is \nnoticed considerably before the thunder. This occurs because the speed of light is faster than \nthe speed of sound. The qualities of the medium through which sound t ravels determine its \nspeed. The medium's elasticity, density, pressure, and temperature can all change. As sound \ngoes from a solid to a gaseous state, its speed reduces. However, in any medium, the speed of \nsound increases as the temperature rises. The tab le shows the sound speed in various mediums \nat different temperatures.  \n  Speed of sound in different media at   \n25\uf0b0 \nState   Substance   Speed in m/s  \nSolids   Aluminium   6420  \nNickel   6040  \nSteel   5960  \nIron  5950  \nBrass   4700  \nGlass(Flint)   3980  \nLiquid   Water (Sea)   1531   \n \n \n    7",
  "Sound.txt\n   7  \n \n  \nWater(distilled)   1498  \nEthanol   1207  \nMethanol   1103  \nGases   Hydrogen   1284  \nHelium   965 \nAir  346 \nOxygen   316 \nSulphur dioxide   213 \n \nReflection of Sound:  \n\u2022 When sound collides with a solid or liquid surface, it bounces back like light rays. The \nrules of reflection and refraction apply to sound waves as well. In order for sound waves \nto reflect, we need a huge surface or obstruction. The rolling of thunder, fo r example, \nis caused by consecutive reflections from clouds and terrain surfaces.  \n\u2022 The directions in which sound is incident and reflected make equal angles with the \nnormal to the reflecting surface, and the three lie in the same plane, according to the \nrule of sound reflection.  \n  \n \n \n    8",
  "Sound.txt\nEchoes:  \nSound waves, like all waves, can be reflected. The enormous obstructions cause sound waves \nto be reflected. An echo is a sound that is heard as a result of a sound wave being reflected by \na huge obstruction. Echo is normally undetectable because the reflec ted sound is integrated \nwith the original sound. To hear an echo clearly, certain requirements must be met (as a \nseparate sound). The experience of any sound lasts roughly  0.1 seconds in our ear. This is \nreferred to as hearing persistence. The original sound and its echo cannot be separated if the \necho is heard within this time span. The most critical criterion for hearing an echo is that the \nreflected sound should reach the ear  only after the original sound has died off for at least  0.1 \nsecond. Because sound travels at 340 metres per second, the distance travelled by sound in  0.1 \nThe second is 34 metres. This distance is twice the minimum distance between a sound source",
  "Sound.txt\nsecond. Because sound travels at 340 metres per second, the distance travelled by sound in  0.1 \nThe second is 34 metres. This distance is twice the minimum distance between a sound source \nand a reflector. If the obstruction is at least 17 metres away, the reflected sound or echo can be \nclearly heard after  0.1Second.  \nFurthermore, for any wave to be reflected, the size of the reflector must be big in comparison \nto the wavelength of the sound, which is on the order of 1 metre for ordinary sound. An echo \ncan be produced by a large building, a mountainside, or a large rock  formation, among other \nthings. In addition, the reflected sound must have sufficient strength or volume to be heard. \nFurthermore, the echo and the original sound should not mix or overlap if the echo is to be \ndifferentiated from the original sound. The or iginal sound, such as a clap or a shout, should be \nvery short in duration for this.",
  "Sound.txt\ndifferentiated from the original sound. The or iginal sound, such as a clap or a shout, should be \nvery short in duration for this.  \nAs a result, the following conditions could be listed for echo formation:  \n\u2022 The obstacle/reflector must be large in comparison to the incident sound wavelength \n(for reflection of sound to take place).  \n\u2022 There should be at least 17 metres between the sound source and the reflector (so that \nthe echo is heard distinctly after the original sound is over).  \n\u2022 The sound's intensity or loudness must be adequate for the reflected sound to be audible \nwhen it reaches the ear. The original sound should only last a few seconds.",
  "Sound.txt\n   9",
  "Sound.txt\nEchoes' Benefits and Drawbacks:  \n\u2022 Echoes can be beneficial or annoying. If the walls and roof of a music hall are not \nappropriately built, echoes might disrupt a performance.   \n\u2022 Echoes can be used to provide critical information if the walls are too hard or too flat \nto reflect sound waves. A ship's sonar device (Sonar stands for sound navigation \nranging) emits high -frequency sound waves to determine how close the ship is to the \nseabed. An ultrasound scanner, which is best known for producing images of an unborn \nbaby, works in a similar way.  \n\u2022 As they fly through the night, bats use echoes to navigate. It works in the same way as \nsonar and ultrasound scanners do. The bat emits a series of small, high -pitched squeaks \nthat bounce off the objects along its route. The bat hears the echoes and change s its \ntrajectory to avoid the obstacles. Many bats have big ears in order to capture as much \nreflected sound as possible.",
  "Sound.txt\ntrajectory to avoid the obstacles. Many bats have big ears in order to capture as much \nreflected sound as possible.  \n\u2022 It's called echo locating when creatures like bats and dolphins use echoes. They use it \nto find their way about and hunt for prey. Some animals use echolocation to determine \nthe size and location of items in their environment.",
  "Sound.txt\n   10  \n \n  \n\u2022 Bats use echolocation to guide them in flying at night. They fire off a series of tiny \n'clicks,' which bounce off things and return to the bat. It creates a \"sound\" image of its \nsurroundings.",
  "Sound.txt\nReverberation:  \n\u2022 A sound made in a large hall will persist due to light reflection until it is lowered to a \nlevel where it is no longer audible.  \n\u2022 Reverberation is the persistence of audible sound caused by successive reflections from \nsurrounding objects after the source has finished producing that sound.  \n\u2022 Excessive reverberation should be avoided. The auditorium's roof and walls are usually \ncoated with sound -absorbing materials like compressed fiberboard, rough plaster, or \ndrapes to lessen reverberation.  \n\u2022 Practical Applications of Reflection of Sound   \nSome applications of the principle of reflection of sound are:   \n\u2022 Megaphone   \n\u2022 Hearing Board   \n\u2022 Sound Boards  \n\u2022 Megaphone: A megaphone is a tube that is formed like a horn. Sound waves are limited \nto the air in the tube due to consecutive reflections that prevent them from spreading \nout. \n\u2022 Hearing Board: Hearing aids are devices used by persons who have difficulty hearing.",
  "Sound.txt\nto the air in the tube due to consecutive reflections that prevent them from spreading \nout. \n\u2022 Hearing Board: Hearing aids are devices used by persons who have difficulty hearing. \nThe sound waves that the hearing aid receives are reflected into a smaller region leading \nto the ear.",
  "Sound.txt\n   11  \n \n  \n\u2022 Sound Boards: Sound waves can be reflected by curved surfaces. In an auditorium, this \nreflection of sound waves is employed to distribute the waves evenly around the space. \nSound Boards are used to reflect sound waves back to the source. The sound board's \nfocal point is where the speaker is positioned.  \n \nMusical Sound and Noise:  \n\u2022 A pleasant continuous and uniform sound created by regular and periodic vibrations is \nreferred to as a musical sound.  \n\u2022 A guitar, piano, tuning fork, and other musical instruments, for example, generate a \npleasing sound.  \n\u2022 Noise is described as an irregular series of discordant and unpleasant to the ear \ndisruptions.  \n\u2022 By hearing the echo of their own sound, bats and dolphins may identify the presence of \nan obstruction. This is referred to as sound -ranging.",
  "Sound.txt\nRange of Hearing:  \nA vibrating source emits sound waves, which are then transported via the air. Sound waves \nbetween 20 Hz and 20 KHz can be heard by the human ear. This range is referred to as the \naudible range. Ultrasonic waves are sound waves with frequencies above the au dible range, \nand they are commonly referred to as ultrasound. Infrasonic waves are sound waves with \nfrequencies lower than the hearing range.  \n \n \n  \n \n \n    12",
  "Sound.txt\n   12  \n \n  \nApplications of Ultrasound:  \n\u2022 It's utilised for medical diagnosis and treatment, as well as surgical procedures.  \n\u2022 Ultrasound is used by bats and porpoises to navigate and find food in the dark.  \n\u2022 It's used to spot a faulty foetus.  \n\u2022 It's employed in the treatment of muscular pain.  \n\u2022 Ultrasonography (a procedure that uses ultrasonic waves to create 3 -dimensional \npictures) is used to pinpoint the exact location of an eye tumour.  \n\u2022 Ultrasound is commonly used to clean spiral tubes, electronic components, and other \nsimilar objects.  \n\u2022 Metal blocks are inspected with ultrasound to discover cracks and faults.",
  "Force And Laws Of Motion.txt\nClass IX Science     1 \nRevision Notes \nClass \u2013 9 Science \nChapter 8 - Force and Laws of Motion \n\u25cfThe motion of objects is based on their displacement, velocity, and\nacceleration. Have you wondered why certain natural phenomena occur and\nwhy they continue to occur in the same way? For example- why do the planets\nmove around the Sun and why does a ball thrown up come back falling down?\nThe answer to this question is force.\n\u25cfForce and Motion\nA force is applied to push the cart, a driver applies force either to stop the car\nor bus or in order to change the speed or direction of motion, and a football\nplayer kicks the ball in order to set it in motion.\nIn all the examples given above, the force is applied on a body that brings\nabout the following changes:\n\u2022 Change in the state of rest of a body or change in its position.\n\u2022 To changes the speed of the body.\n\u2022To change the direction of motion of a body.",
  "Force And Laws Of Motion.txt\nabout the following changes:\n\u2022 Change in the state of rest of a body or change in its position.\n\u2022 To changes the speed of the body.\n\u2022To change the direction of motion of a body.\n\u25cfForce is defined as any external agent that changes the state of rest or uniform\nmotion of a body along a straight line.\n\u25cfResultant Force:\nAny object can be moved by the application of force. Several forces can act\nsimultaneously on a single body. For instance, several people trying to move\na boulder whereas a strong person can move the same boulder all by himself.\nIn this case, the force applied by the strong man has the equal effect as that\nproduced by the net force applied by all persons. Therefore, the force applied\nby the strong man is said to be the resultant force. The resultant force is \u201cwhen\na force acting on a body produces the same effect as that produced by a\nnumber of forces.\u201d",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             2 \nFour people people can jointly move a boulder  \nF=F1 +F2 +F3 +F4  \n\u25cf Balanced and Unbalanced Forces  \nThe above depicts a block of wood kept on the table. This block is pulled from \npoint A, it starts to move towards the left. When a block is pulled at the point \nB it moves towards the right.  \n1. Example of Unbalanced Forces  \nIf the block is pulled from both  sides with the same force then the block \nremains stationary (i.e at its position). The forces applied are unequal and \nopposite to each other. The resultant of the forces acting on this block is now \nnot zero as block will shift.   \n2. Example of Balanced Forces  \nIn tug of war games when both the teams start pulling the rope with equal and \nopposite forces, then the rope remains in place as the forces acting on it are \nequal and opposite and their resultant becomes zero.",
  "Force And Laws Of Motion.txt\nopposite forces, then the rope remains in place as the forces acting on it are \nequal and opposite and their resultant becomes zero.  \n3. Example of Balanced  Forces  \nWhat do you observe when you squeeze a rubber ball between the palms of \nyour hands. The shape of the rubber ball changes due to the forces applied on \nthe ball are equal and opposite and the resultant of these forces does not lead \nto its motion inst ead the object gets deformed and continues to be as long as \nthe force is applied. However, this is temporary deformation.",
  "Force And Laws Of Motion.txt\n\u25cf Galileo's Observation and Origin of Newton Mechanics  \nAristotle believed that the natural state of bodies is a state of rest. Galileo \nopposed this belief. Galileo observed when a ball rolls down on an inclined \nplane, its speed is increased. In the same way, when rolled up the inclined \nplane, its speed decreased. He then rolled the ball on a horizontal plane. \nGalileo repeated this experim ent on a smooth surface. He noticed that the ball \ncontinued to move. Galileo suggested that the speed of the ball moving on a \nhorizontal plane remains constant when no external force or force of friction",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             3 \nacts on it. Galileo noticed that it is the natural t endency of all bodies to oppose \nany change in their state of rest or motion.  \nForce and Laws of Motion  \n\u25cf Inertia  \nGalileo's experiments showed that all objects have a tendency to continue in \ntheir state of rest or of uniform motion unless an external force is applied to \nit. The examples given below will help you understand the observations of \nGalileo's experiment:  \n\u25cf Place a cardboard on an empty tumbler and keep a coin on the cardboard as \ngiven in the figure.  \nCardboard and a Coin placed on Tumblr",
  "Force And Laws Of Motion.txt\n\u25cf Now, Flick the cardboard with your finger. What do you see? The coin kept \non the cardboard drops into the tumbler. On flicking the cardboard moves fast \nwhereas the coin continues in its state of rest and hence drops into the tumbler.  \n\u25cf A passenger standing i n a moving bus leans forward when brakes are applied \nsuddenly. This is because the body of the person is in motion along with the \nbus. When the bus stops all of a sudden, the lower part of the body comes to \nrest with the bus but the upper part of the body remains in motion.",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             4 \n\u25cf From the above examples, we see that the objects continue to remain in their \nstate of rest or of uniform motion until an external force is applied. The \ntendency of an object to resist any change in its state of rest or of uniform \nmotion is known as inertia.  \n\u25cf Inertia is the property of the body by virtue of which it opposes any sort of \nchange in its state of rest or uniform motion along a straight line.  \nInertia is classified into:  \n1.  Inertia of rest - Some examples to it: A passenger standing in a bus \nleans backwards when brakes are applied suddenly, fruits falling down \nfrom the tree when it is shaken, dust particles on a carpet when it is \nbeaten with a stick.  \n2. Inertia of motion - Example to this is man alighting from a moving train \nleans forward . \n3. Inertia of direction - For example, water particles stuck to the cycle tyre",
  "Force And Laws Of Motion.txt\nbeaten with a stick.  \n2. Inertia of motion - Example to this is man alighting from a moving train \nleans forward . \n3. Inertia of direction - For example, water particles stuck to the cycle tyre \nand fly off tangentially, when a drive takes a turn, the passenger feels \nthe force away from the centre of the curve.",
  "Force And Laws Of Motion.txt\nThe inertia of a body depends on the mass of the body. Heav y objects possess \nmore inertia than lighter ones.  \n\u25cf Newton gave the three basic laws of motion  \n1.  First law of motion: The first law of motion states that \"A body continues to \nbe either in a state of rest or of uniform motion along a straight line unless an \nexternal force is applied on it.\" This tells that every object has a \ntendency(inertia) to resist any change in its state of rest or motion This law is \ntherefore known as law of inertia. This law explained the qualitative definition \nof force.  \n\u25cf Momentum: A cricket ball moving with a constant velocity v so is tennis ball. \nWe apply more force in order to stop the cricket ball than to stop the tennis \nball since the mass of the cricket ball is more than the tennis ball. The force \nrequired in order to  stop a moving object depends on the mass of the object. \nThe force required to stop a moving body is directly proportional to its \nvelocity.",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             5 \nMomentum: It is defined as the product of the mass and velocity of the object \nor body. It is a vector quantity and direction of momentum will be the same \nas that of velocity. It is represented by p.  \np = mv here, m= mass of the object, v is velocity. SI unit=kg m/s.  \n2. Newton's Second Law of Motion  \nNewton's second law of motion tells that the rate of change of momentum is \ndirectly proportional to the applied force and takes place in the same direction \nas the applied force.  \nExplanation:  \nConsider a body of mass \nm , with initial velocity \nu . The body is applied by \nforce \nF  for time \nt , and its fi nal velocity is \nv . \nHence, Initial momentum \nmu\uf03d  \nand, Final momentum = mV  \nTherefore, Change in momentum in time \nt m(v u)\uf03d\uf02d  \nChange in momentum in unit time \n()m v u\uf03d\uf02d  \nBut since we know \nv u a\uf02d\uf03d  (acceleration) \nt",
  "Force And Laws Of Motion.txt\nmu\uf03d  \nand, Final momentum = mV  \nTherefore, Change in momentum in time \nt m(v u)\uf03d\uf02d  \nChange in momentum in unit time \n()m v u\uf03d\uf02d  \nBut since we know \nv u a\uf02d\uf03d  (acceleration) \nt  \nNow, Change in momentum in unit time \nma\uf03d  Or \nAccording to Newton's second law,  \nRate of change of momentum \nF  \nFK\uf03d",
  "Force And Laws Of Motion.txt\nma (Here, \nK\uf03d  constant of proportionality)  \nIf a body has unit mass and unit acceleration, then the force possessed by it is \nalso one unit.  \nF=ma  \nForce = - mass \u00d7 acceleration [The negative sign is an indication of the gun \nrecoiling]",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             6 \n\u25cf One Newton force is equal to a for ce that produces an acceleration of 1 m/s2 \non an object of mass 1 kg. Force is also a vector quantity. Newton's second \nlaw of motion stated the quantitative definition of force.  \n\u25cf Impulse:  \nThe mathematical representation second law of motion is F = mv\u2212mu/t,  \nFt = mv - mu \nWhen forces acting on a body for a short interval of time then it is defined as \nan impulse.  \nSI unit of impulse = kg m/s.  \nWhen a person kicks a football, the kick lasts only for seconds. This force is \nan example for impulsive force.  \n\u25cf Newton\u2019s T hird Law of Motion  \nAction and reaction forces are equal but act simultaneously on different \nbodies. A rubber ball rebounds when back when it is thrown on a hard floor. \nThis is due to the action and reaction forces that are acting simultaneously.",
  "Force And Laws Of Motion.txt\nbodies. A rubber ball rebounds when back when it is thrown on a hard floor. \nThis is due to the action and reaction forces that are acting simultaneously. \nThe ball a pplies a force (action force) on the floor whereas the floor exerts an \nequal and opposite force (reaction force) on the ball. The rubber ball being \nlight rebounds. Newton's third law of motion states that \u201cTo every action, \nthere is an equal and opposite re action\".  \n\u25cf Some day to day examples of newton's third law of motion:  \n1. While walking on the ground, our foot pushes the ground backward (action \nforce) whereas the ground in turn exerts a force on the foot (reaction force) \ncausing the foot move forward.  \n2. When a person jumps from a diving board he pushes the diving board (action \nforce) whereas the board, in turn, pushes the man forward in the opposite \ndirection (reaction force).  \n3. The birds in sky push the air with their wings (action force) whereas the air,",
  "Force And Laws Of Motion.txt\nforce) whereas the board, in turn, pushes the man forward in the opposite \ndirection (reaction force).  \n3. The birds in sky push the air with their wings (action force) whereas the air, \nin turn , exerts a force on the bird in the upward direction (reaction force).",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             7 \n4. A swimmer pushes the water in the backward direction (action force) whereas \nthe water exerts a force on the swimmer (reaction force) which pushes him \nforward.  \n \nThe action and reaction f orces are equal and opposite but their resultant is not \nzero as the action and reaction forces are acts on two different bodies. \nNewton's third law holds when the interacting bodies are at rest or in motion. \nNewton's third law gives the relationship betwee n interacting forces between \nthe two objects but does not give the magnitude of force.  \n\u25cf Law of Conservation of Momentum  \nAccording to Newton's third law of motion, action and reaction forces result \nin a change in velocities of both the bodies which change th e momentum of \nthese bodies as well.",
  "Force And Laws Of Motion.txt\n\u25cf Applications of Law of Conservation of Momentum  \n1. The recoil of a Gun  \nWhen a bullet is fired from a gun, the gases produced in the barrel exert a lot \nmore of a force on the bullet (action force). As a result, the bullet moves \nforward with a high velocity known as the muzzle velocity. The bullet exerts \nan equal and opposite f orce on the gun(reaction force). The gun moves \nbackward. This backward motion of the gun is, the recoil of the gun. The \nvelocity with which the gun moves backward is the recoil velocity of the gun.  \n2. The motion of a rocket  \nA rocket is a projectile that carri es the rocket fuel and oxidizer, which supplies \noxygen required for combustion. Liquid hydrogen is generally used in rocket \nfuels whereas hydrogen peroxide, liquid oxygen are used as oxidizers. The \nfuel-oxidizer combination in a rocket is known as the prop ellant.  \nA rocket consists of a combustion chamber in which either a solid or liquid",
  "Force And Laws Of Motion.txt\nfuel-oxidizer combination in a rocket is known as the prop ellant.  \nA rocket consists of a combustion chamber in which either a solid or liquid \npropellant is burnt. A nozzle is present at its tail through which the gaseous \nproducts produced during combustion escape out. The rocket forces a jet of \nhot gases downward s by the nozzle. This acts as action. The jet of gases exerts",
  "Force And Laws Of Motion.txt\nClass IX Science                                                                                             8 \na force on the rocket, pushing it (reaction). This force leads to forward \nacceleration.  \n3. Rocket Propulsion  \nJust before the launch, the momentum of the rocket is zero. When the rocket \nis fired, it  forces a jet of hot gases with a very high velocity down the nozzle. \nThe jet of gases has momentum downwards. Therefore, the rocket has a \nmomentum of equal magnitude but in opposite direction. Therefore the rocket \ngoes upwards. In multi -stages propulsion takes place in rockets when the fuel \nof the first stage gets used completely, the rocket casing gets detached and is \ndropped off and the second stage is ignited.",
  "Tissues.txt\nClass IX Science                                                                                                1 \nRevision Notes  \nClass \u2013 9 Science  \nChapter 6 - Tissues",
  "Tissues.txt\n\u25cf Plants can not move from one place to another i.e. show locomotion to meet \ntheir requirements. Therefore they are provided with some tissues which are \nmade up of dead cells, which helps in providing mechanical strength. They \nhave the ability to withstand u nfavourable conditions like strong winds, \nstorms, floods, etc.  \n\u25cf Animals on the other hand can move from one to another in search of food, \nmates, or shelter. They have to consume more energy in comparison to plants. \nMost of the tissues present in them are li ving. Cell growth seen in animals is \nvery uniform. The structural organisation of organs and organ systems is quite \nspecialized and localized in animals in comparison to complex plants.  \n\u25cf Plant tissues:  \n1. Meristematic Tissue  \nThe growth in plants occurs a t very specific regions. This is due to the \npresence of dividing tissue commonly known as meristematic tissue. On the \nbasis of the region where they are present, meristematic tissues are further",
  "Tissues.txt\npresence of dividing tissue commonly known as meristematic tissue. On the \nbasis of the region where they are present, meristematic tissues are further \nclassified as apical, lateral, and intercalary.  \na.  Apical meris tem is the meristem present at the apical or growing area \nmainly the tips of stems and roots. Apical meristem is responsible for \nthe increase in the length of the plant.  \nb.  Lateral meristem is generally found in the radial portion of the stem or \nroot. Latera l meristem is responsible for the increase in the girth of the \nplant.  \nc. Intercalary meristem appears at the base of the leaves or at the \ninternodes. Intercalary meristem causes an increase in the length of the \ninternode.  \n2. Permanent Tissue",
  "Tissues.txt\nClass IX Science                                                                                                2 \nThe older meristematic cells tends to lose the capacity to divide and turns to \npermanent tissues. This process of attaining a permanent shape, size, and \nfunction is known as differentiation.  \nThese cells have lost their capacity to divide but now perform a specified \nfunctions to provide strength, flexibility and elasticity to the plant. These \ntissues are divided into simple permanent, complex permanent and special \ntissues.  \n\u25cf Simple permanent are divided into the parenchyma, collenchyma and \nsclerenchyma and  these are divided on the basis of their function.  \n\u25cf Parenchyma: Parenchyma are living cells and are loosely packed. It plays a \nrole in supporting the plant and stores food. In some cases it may contain \nchlorophyll also and perform photosynthesis and t hen it is known to be",
  "Tissues.txt\nrole in supporting the plant and stores food. In some cases it may contain \nchlorophyll also and perform photosynthesis and t hen it is known to be \nchlorenchyma. Parenchyma when contains large air cavities in like in aquatic \nplants, then it is known as aerenchyma. The aerenchyma helps in providing \nbuoyancy in aquatic plants.  \n\u25cf Collenchyma : Collenchyma are elongated living  cells with very small \nintercellular spaces. Their cell walls consists of cellulose and pectin. \nCollenchyma mainly occurs in the peripheral regions of stems and leaves in \norder to provide mechanical support and flexibility to plants.  \n\u25cf Sclerenchyma: These ar e long, dead cells with deposition of lignin in their \ncell wall and have no intercellular spaces. Sclerenchyma is found in the \nvascular tissues in stems, in veins of leaves, and in the hard covering of seeds \nand nuts. They are responsible for providing str ength to the plant.",
  "Atoms and Molecules.txt\nClass IX Science   1 \nRevision Notes  \nClass 9 Science  \nChapter 3 - Atoms and Molecules  \nSummary of Atoms and Molecules:  \nLaw of conservation of mass:  \n\u25cfIn a chemical action, the law of conservation of mass stipulates that mass\ncan not be created or destroyed .\n\u25cfAccording to this law, the overall mass  of the products remains equal to\nthe total mass of the reactants  after any physical or chemical change.\nLaw  of constant proportion:  \nThis law was expressed by another French chemist, Joseph Proust , as \nfollows: \"A chemical compound always comprises the same elements \nmixed in the same  proportion by mass.\"  \nLaw of multiple proportion:  \nAs established by John Dalton, when two elements combine to form two \nor more compounds, the mass of the element that combines with the fixed \nmass of the other bears a simple whole number ratio \n( )1803 .\nDalton\u2019s atomic theory:  \n\u25cfAccording to Dalton's atomic theory, all matter, whether an element, a",
  "Atoms and Molecules.txt\nmass of the other bears a simple whole number ratio \n( )1803 .\nDalton\u2019s atomic theory:  \n\u25cfAccording to Dalton's atomic theory, all matter, whether an element, a\ncompound, or a mixture, is made up of microscopic particles called atoms .\n\u25cfThis theory's postulates  are as follows::\n1.All matter is made up of atoms , which are very small tiny  particles\nthat engage in chemical reactions.\n2.In a chemical reaction, atoms are indivisible  particles that cannot be\nformed or destroyed.\n3.A given element's atoms have the same mass  and chemical\ncharacteristics .\n4.The masses and chemical characteristics of at oms of various\nelements differ.\n5.Compounds  are formed when atoms join in a ratio of tiny whole\nnumbers.Class IX Science   2 \n6.In a given compound, the number and types of atoms  remain\nconstant .\nAtom:  \n\u25cfAn atom is an element's defining structure that can't be broken chemically.\n\u25cfThe electron, proton , and neutron  are the three particles that make up an\natom.",
  "Atoms and Molecules.txt\nconstant .\nAtom:  \n\u25cfAn atom is an element's defining structure that can't be broken chemically.\n\u25cfThe electron, proton , and neutron  are the three particles that make up an\natom.\n\u25cfThe nucleus  is the nucleus of the atom.\n\u25cfAn atom's nucleus  holds the entire mass  of the atom.\n\u25cfAn atom's electrons  are grouped in shells/orbitals .\n\u25cfThe atomic symbol is made up of three parts:\nThe symbol \nX  - standard element symbol;\nThe atomic number \nA - represents the number of protons;\nThe mass number  \nZ - represents the total amount of protons and neutrons\nin an element.\n\u25cfThe radius of an atom  is measured in nanometres .\nAtomic Mass:  \n\u25cfThe atomic mass was proposed by Dalton  as an atomic hypothesis.\n\u25cfThe average mass of an atom, or a set of atoms, is the sum of the masses\nof the electrons, neutrons, and protons .\n\u25cfThe atomic mass is the mass of an atomic particle.\n\u25cfThis is often stated in terms of a unified atomic mass unit, as per the\ninternational agree ment ( AMU ).",
  "Atoms and Molecules.txt\n\u25cfThe atomic mass is the mass of an atomic particle.\n\u25cfThis is often stated in terms of a unified atomic mass unit, as per the\ninternational agree ment ( AMU ).\n\u25cfThe average mass of one atom of an element, as compared to\n1\n12  th the \nmass of one carbon - \n12 atom, is called atomic mass .\nValency:  \n\u25cfThe electrons in the atom's outermost orbit  are referred to as valence\nelectrons .\n\u25cfThe valency of an atom is determined by its ability to lose, gain, or share\nvalence electrons in order to complete its octet.\nMolecule:  \n\u25cfThe total of the masses of the elements present in a molecule is the\nmolecule's molecular mass .\n\u25cfThe atomic mass of an element is multiplied by the number of atoms in the\nmolecule, and the masses of all the elements in the molecule are added to\nget the molecule's mass.Class IX Science   3 \n\u25cfThe number of atoms in a single molecule of an element is known as its\natomicity .\n\u25cfFor example, each of the molecules of hydrogen, nitrogen, oxygen,",
  "Atoms and Molecules.txt\n\u25cfThe number of atoms in a single molecule of an element is known as its\natomicity .\n\u25cfFor example, each of the molecules of hydrogen, nitrogen, oxygen,\nchlorine, iodine, and bromine has two atoms , and hence they all have two\natomicity  each.\nCompound:  \n\u25cfWhen two or more elements join chemically in a defined mass ratio, the\nresult is known as a compound .\n\u25cfCompounds are substances made up of two or more different types of\natoms in a specific ratio.\nIons:  \n\u25cfAn ion is an atom or molecule with a net positive or negative charge due\nto the gain or loss of one or more of its valence electrons.\n\u25cfA negatively charged particle is an anion , and a positively charged particle\nis a cation .\n\u25cfIonic compounds  are chemical compounds in which ions are held together\nby ionic bonds , which are a type of specialised bond.\n\u25cfThe positive and negative charges in an ionic substance are always in equal\namounts.\nMolecular Mass:  \n\u25cfThe total of the masses of the elements present in a molecule is known as",
  "Atoms and Molecules.txt\n\u25cfThe positive and negative charges in an ionic substance are always in equal\namounts.\nMolecular Mass:  \n\u25cfThe total of the masses of the elements present in a molecule is known as\nthe molecule's molecular mass .\n\u25cfThe atomic mass of an element is multiplied by the number of atoms in the\nmolecule, and then the masses of all the elements in the molecule are\nadded .\nMole & Avogadro Number:  \n\u25cfA mole  is the amount of entities existing in a substance, such as atoms,\nmolecules, and ions.\n\u25cfA mole is \n236.022\u00d710  molecules of any substance.  \n\u25cfOne of the most practical ways of describing the amount of reactants and\nproducts in a reaction is to use the mole idea.\n\u25cfAvogadro's number  has a value of about  \n236.022\u00d710 . \n\u25cfAvogadro's number is a formula that calculates the number of particles in\none mole (or mol) of a substance.\n\u25cfIt's possible that these particles are electrons, molecules, or atoms.\n\u25cfNo. of Moles can be calculated as;Class IX Science   4",
  "Atoms and Molecules.txt\none mole (or mol) of a substance.\n\u25cfIt's possible that these particles are electrons, molecules, or atoms.\n\u25cfNo. of Moles can be calculated as;Class IX Science   4 \nMass of a substance1 Mole = Gram atomic mass\nAMolecular Weightn = Empirical Formula Weight\nGiven No. of particlesn = Avogadro Number\nNn = NSome Important formulae:  \n\u25cf \nGiven MassNo. of Molecules =  \u00d7 Avogadro NumberMolar Mass\nHence,  \nAmN =  \u00d7 NM\n\u25cf \nMass of a substance1 Mole = Gram atomic mass\n\u25cf \nMolar Mass of a substanceMass of a substance = No. of Moles\n\u25cf \nTotal weight of element in a moleculePercentage composition of an Element = 100Gram Molecular Weight\uf0b4\n\u25cf \n( )12Mass of one molecule of the substanceRMM = 1 Mass of the atom of Carbon C12\uf0e6\uf0f6\uf0e7\uf0f7\uf0e8\uf0f8\n\u25cf \nGram Molecular WeightGram Molecular Volume = Weight / Volume of gas at STP",
  "Structure of the Atom.txt\nClass  VIII Science    1  \n \n \nRevision Notes  \nClass 9 Science  \nChapter 4 \u2013 Structure of Atoms",
  "Structure of the Atom.txt\nSummary of Structure of Atoms  \n\u2b9a Atoms are the basic units of matter  and the defining structure of elements. \nIt consists of three basic particles i.e., protons, electrons and neutrons  that \nbuild the structure of an atom.  \n\u2b9a Protons are positively  charged particles and were  founded by E. Goldstein.  \n\u2b9a Electrons are negatively  charged particles and are founded by J.J. Thomson.  \n\u2b9a Neutrons have  no charge  and are founded by Chadwick.  \n\u2b9a Nucleus  is in the centre of the atom and contains protons and neutrons . \n\u2b9a The outer region of the atom which holds electrons in orbit around the \nnucleus is known as shell/energy level/orbits .  \n\u2b9a These shells are further divided into subshells.  \n\u2b9a The electrons present in the outermost shell of an atom are known as the \nvalence electron s. \n\u2b9a The electronic configuration  of an element is the representation of the \narrangement of electrons distributed among the orbital shells and subshells.",
  "Structure of the Atom.txt\nvalence electron s. \n\u2b9a The electronic configuration  of an element is the representation of the \narrangement of electrons distributed among the orbital shells and subshells. \nThe valence electrons are the determining factor for the unique chemistry of \nthe element.  \n\u2b9a The atomic number  of an element is the same as the number of protons in \nthe nucleus of its atom. As atoms are electrically neutral, an atom contains as \nmany electrons as it has protons. Atomic number is denoted by Z.  \n\u2b9a The mass number  of an atom is equal to the  number of nucleons in its \nnucleus. Nucleons is the collective term  for protons and neutrons. Mass \nnumber is denoted by A.  \n\u2b9a In the notation of an atom the atomic number is written as  a subscript on the \nleft of the element symbol and the mass number is writt en as a superscript on \nthe left of the element symbol.  \n\u2b9a Isotopes can be defined as elements that possess the same number of protons \nand electrons, but a different number of neutrons.",
  "Structure of the Atom.txt\nthe left of the element symbol.  \n\u2b9a Isotopes can be defined as elements that possess the same number of protons \nand electrons, but a different number of neutrons.  \nFor example: Protium, deuterium, and tritium are the isotopes of hydrogen. \nThey each have one single proton \n() Z1=  and single electron, but differ in  \n Class  VIII Science    2",
  "Structure of the Atom.txt\nthe number of their neutrons. Hydrogen has no neutron, deuterium has one, \nand tritium has two neutr ons. \n\u2b9a Isobar is that element which differs in the chemical property but has the \nsame physical property which means isobars are those elements which have \na different atomic number but the same mass number.   \nFor example: Calcium and chlorine are isobars since both have mass number \n40\n but calcium has atomic number \n20  and chlorine has atomic number \n17 . \n\u2b9a Isotones are the elements that have the  same number of neutrons but \ndifferent atomic numbers.  \nFor example:  Chlorine with atomic number \n37  and potassium with atomic \nnumber \n39  are isotones, because both chlorine and potassium have same \nnumber of neutrons i.e., \n20 .",
  "Motion.txt\nClass IX Science     1 \nRevision Notes \nClass 9 Science  \nChapter 7 - Motion \nIntroduction \n\u2022 One of the most common phenomena in the physical world is motion. Mechanics\nis the branch of Physics that deals with the behavior of moving objects.\n\u2022 Mechanics is divided further in to two sections: Kinematics and Dynamics.\n\u2022 Kinematics is the study of motion without regard for the cause of motion.\n\u2022 Dynamics is concerned with the source of motion, which is force.\nMotion and Rest  \n\u2022 An object is said to be in motion if its position in relation to its surroundings\nchanges in a given time.\n\u2022 An object is said to be at rest if its position in relation to its surroundings does not\nchange.\n\u2022 A frame of reference is another object or scene against which we compare the\nposition of an object.\nFigure 1  \n \nClass IX  Science                                                                                             2 \n \nFigure - 2",
  "Motion.txt\nClass IX  Science                                                                                             2 \n \nFigure - 2 \n \nTake a look at the numbers. Figure 1 shows the car to the right of the tree. Figure 2 \nshows the car to the left of the tree after 2 seconds. The car must have moved from \none location to another because the tree does not move. As a result, the tree serves \nas the frame of reference in this case.   \n \nTypes of Motion   \nThere are three types of motion:   \n\u2022 Translatory motion   \n\u2022 Rotatory motion",
  "Motion.txt\nTypes of Motion   \nThere are three types of motion:   \n\u2022 Translatory motion   \n\u2022 Rotatory motion   \n \n \nClass IX  Science                                                                                             3 \n\u2022 Vibratory motion   \nTranslatory Motion   \n\u2022 A particle in translatory motion moves from one point in  space to another. This \nmovement may be in a straight line or in a curved path.  \n\u2022 Rectilinear motion is defined as motion along a straight line.  \n\u2022 Curvilinear motion is defined as movement along a curved path.  \n\u2022 As an example, consider a car driving down a  straight road.  \n \n \nRectilinear Motion   \nExample:  A car negotiating a curve   \n \n \n \n \nClass IX  Science                                                                                             4 \nCurvilinear Motion   \nRotatory Motion   \nThe particles of the body describe concentric circles around the axis of motion in \nrotatory motion.",
  "Motion.txt\nVibrational Motion  \nParticles in vibrat ory motion move back and forth around a fixed point.  \n \n \nDistance and Displacement   \n \n \nClass IX  Science                                                                                             5 \nThe distance between termini A and B is 150 kilometers. A bus connects Terminus \nA and Terminus B. The bus travels a distance of 150 kilometers. The bus returns \nfrom terminus  B to terminus A along the same route. As a result, the total distance \ntraveled by the bus from A to B and then from B to A is 150 km + 150 km = 300 \nkm.",
  "Motion.txt\nA bus traveling from point A to point B and back again.  \n\u2022 The distance traveled by a moving object i s the length of the path the object \ntakes.  \n\u2022 The measure of distance is a scalar quantity. The meter is the SI unit of distance.  \n\u2022 The bus's position changed when it moved from Terminus A to Terminus B. The \ndistance between A and B is 150 kilometers. The d istance traveled on the return \ntrip is also 150 kilometers.  \n\u2022 Displacement is the shortest path covered by a moving object in a specified \ndirection from the point of reference (the initial position of the body).  \nNote:   \n\u2022 However, the displacement when the bus moves from A B to B B is zero. The \nmeter is the SI unit of displacement.  \n\u2022 Displacement is a vector, which means that it is represented by a number with \nappropriate units and direction.  \n\u2022 To emphasize the distinction between displacement and distance, consider a few \nmore examples.",
  "Motion.txt\nappropriate units and direction.  \n\u2022 To emphasize the distinction between displacement and distance, consider a few \nmore examples.  \nAssume a person moves 3 meters from point A to point B and 4 meters from point \nB to point C, as shown in the figure. He has travelled a total distance of 7 meters. \nBut is he really 7 meters away from his starting point? No, he  is only 5 meters",
  "Motion.txt\nClass IX  Science                                                                                             6 \naway from his initial position, implying that he is displaced by the shortest distance \nbetween his initial and final positions.  \n \n \nDistance and Displacement   \nTo determine the displacement in this example, we can use Pythagoras' theorem. \nConsider an object that is changing its position with respect to a fixed point known \nas the origin 0.   \nix\n and \nfx  are the initial and final positions of the object. Then the displacement of \nthe \nobject \nfixx\uf03d\uf02d  \nCase 1  \nSuppose the object is travelling from \n1\uf02b  to \n4\uf02b , then displacement  \nfixx\uf03d\uf02d\n \n4 ( 1)\uf03d\uf02b \uf02d \uf02b\n \n3\uf03d\uf02b\n \n \n \n \nClass IX  Science                                                                                             7",
  "Motion.txt\n4 ( 1)\uf03d\uf02b \uf02d \uf02b\n \n3\uf03d\uf02b\n \n \n \n \nClass IX  Science                                                                                             7 \n \nDisplacement: Case1   \nCase  2  \nIf the object is travelling from -3 to -1, then displacement   \nIf the object is travelling from \n3\uf02d  to \n1\uf02d , then displacement  \nfixx\uf03d\uf02d\n \n1 ( 3)\uf03d\uf02d \uf02d \uf02d\n \n2\uf03d\uf02b\n \n \nDisplacement: Case 2   \nCase 3   \nIf the object is travelling from +4 to +2, then displacement   \nfixx\uf03d\uf02d\n \n2 (4)\uf03d\uf02b \uf02d\n \n2\uf03d\uf02d\n \n \n \n \nClass IX  Science                                                                                             8 \n \nDisplacement: Case 3  \n \nCase 4   \nIf the object follows the path depicted in the figure, the final and initial positions \nare the same, implying that the displacement is zero.",
  "Motion.txt\nDisplacement: Case 3  \n \nCase 4   \nIf the object follows the path depicted in the figure, the final and initial positions \nare the same, implying that the displacement is zero.\n \nDisplacement: Case 4   \nWe can conclude from the preceding examples that a body's displacement is \npositive if its final position is on the right side of its  initial position and negative if \nits final position is on the left side of its initial position. The displacement of a \nmoving object is said to be zero when it returns to its original position. Consider an \nathlete running in a clockwise direction along a circular track with radius r,  \nbeginning at A  \n \n \nClass IX  Science                                                                                             9 \n.  \nA Circular Track of Radius r",
  "Motion.txt\nClass IX  Science                                                                                             9 \n.  \nA Circular Track of Radius r   \n \nWhat is the athlete's total distance travel led when he arrives at point B?  \nThe athlete's total distance traveled when he arrives at point B equals to half of the \ncircumference o f the circular track, that is, \n2\n2rr\uf070\uf070\uf03d . \nDisplacement \n2 AB r\uf03d \uf03d \uf03d  Diameter of circle (the shortest distance between the \ninitial and final positions).  \nIf the athlete arrives at the starting point \nA , the distance covered is equal to the \ncircumference of the circular track, i.e., \n2.r\uf070  However, the displacement is zero \nbecause the athlete's initial and final positions are the same.  \n \nDifference between Distance and Displacement  \nDistance  Displacement  \nIt is the actual length of a \nmoving object's path.  It is the shortest distance between the moving \nobject's initial and final positions.",
  "Motion.txt\nClass IX  Science                                                                                             10 \nScalar quantity  Vector quantity  \n \nMotion   \nUniform Motion and Non -uniform Motion   \nThe distances co vered by car A and car B with respect to time is given below:  \nCar A   \nTime in seconds  0 5 10 15 20 25 30 35 \nDistance covered in meters  0 10 20 30 40 50 60 70 \n \nCar B   \nTime in seconds  0 5 10 15 20 25 30 35 \nDistance covered in meters  0 10 15 20 30 60 65 75 \nThe car A travels equal distances in equal time intervals, whereas the car B does \nnot travel equal distances in equal time intervals. That is, car A's motion is an \nexample of uniform motion, whereas car B's motion is an example of non -uniform \nmotion.  \nA body is said to describe uniform motion when it covers equal distances in equal \nintervals of time.  \nWhen a body moves unequal distances in equal time intervals, or vice versa, this is \nreferred to as non -uniform motion.",
  "Motion.txt\nSpeed    \n \nClass IX  Science                                                                                             11 \nRam and Krishna compete in vari ous races over varying distances. Ram covers \n1000\u00a0 m\n in 20 minutes and Krishna covers \n700\u00a0 m  in 10 minutes. Who is the fastest?  \nTo determine who is faster, we will calculate the distance they cover in one \nminute.  \nDistance covered by R am in one minute \n1000\u00a0 m500\u00a0 m / min20\u00a0 min\uf03d\uf03d  \nDistance covered by Krishna in one minute \n700\u00a0 m70\u00a0 m / min10\u00a0 min\uf03d\uf03d  \nKrishna covered more ground in the same amount  of time. We conclude that \nKrishna is the faster of the two.   \nSpeed is defined as the distance travel led by a moving object in one unit of time.  \n distance S speed  time t\uf03d\uf03d\n \nWhere S denotes the di stance travel led and t denotes the time spent.  \nThe SI unit of speed is millimeters per second (m/s). Speed is defined as a scalar \nquantity.",
  "Motion.txt\nWhere S denotes the di stance travel led and t denotes the time spent.  \nThe SI unit of speed is millimeters per second (m/s). Speed is defined as a scalar \nquantity.  \n \nUniform Speed  \nThe graph depicts the distance travel led by a ball every 2 seconds.  \n \nEvery 2 seconds, the ball travels  10 meters. At any point between A and E, the ball \nmoves at a speed of 5 m/s. The object is moving at a constant speed.  \nIf an object travels the same distance in the same amount of time, it is said to be \nmoving at a uniform speed.  \nSurface friction or resis tance is ignored in this case.  \n \n \nClass IX  Science                                                                                             12 \nVariable Speed or Non -Uniform Speed   \nThe distance covered varies with time.",
  "Motion.txt\nVariable Speed   \nFor example, when a rubber ball is dropped from a certain height (h 1), it bounces \nup to a height less than the initial one (h 2). It keeps bouncing, but the height to \nwhich it rises keeps decreasing (h 3, h4). The ball's distance traveled per unit time \ndecreases. The ball's speed varies from point to point. This type of speed is known \nas variable speed.  \n \nAverage Speed and Instantaneo us Speed  \nWhen we travel by car, the speed varies depending on the road conditions at the \ntime. The speed is calculated in this case by dividing the total distance traveled by \nthe vehicle by the total time required for the journey. This is known as the ave rage \nspeed.   \nThe average speed of an object traveling S 1 in time t 1, S2 in time t 2, and S n in time \ntn is given by,  \n1 2 3 n\n1 2 3 nS S S S Average speed t t t t\uf02b \uf02b \uf02b\uf0bc\uf02b\uf03d\uf02b \uf02b \uf02b\uf0bc\uf02b",
  "Motion.txt\nWhen we say that the car travels at an average speed of 60 km/h, we do not mean \nthat it will travel at that speed for the duration of the journey. The actual speed of \nthe car may be less than or greater than the  average speed at a given location.  \n \n \nClass IX  Science                                                                                             13 \nThe speed of a moving body at any given point in time is referred to as \ninstantaneous speed.  \n \nVelocity  \nThe diagram below depicts the various routes Shyam can take from his house to \nschool.   \n \nShyam drives himself to sch ool every day, averaging 60 km/h. Is it possible to find \nout how long it will take to get to the destination? Yes, you can use the relation to \ndetermine the time.  \n distance  speed  time \uf03d",
  "Motion.txt\nBut you don't know what path he w ould have taken. As a result, simply providing \nthe speed of a moving object does not allow one to determine the exact position of \nthe object at any given time. As a result, there is a need to define a quantity that \nhas both magnitude and direction.  \nStartin g with A, consider two objects P and Q. Allow them to travel equal \ndistances in equal time intervals, i.e. at the same speed. Can you guess where each \nof them will be in 20 seconds? P and Q are free to move in any direction. To \ndetermine the exact position  of P and Q, we must also know their direction of \nmotion.  \n \n \n \nClass IX  Science                                                                                             14 \nPictorial Representation of the Position of the Objects P and Q",
  "Motion.txt\nClass IX  Science                                                                                             14 \nPictorial Representation of the Position of the Objects P and Q  \n \nAs a result, another physical quantity known as velocity is introduced to provide us \nwith an idea of both speed and direction.  \nVelocity is defined as the distance trave lled in a given direction by a moving object \nin a given time or speed in a given direction.  \n distance travelled in a specified direc tion ( )velocity( ) time taken ( )svt\uf03d\n \nNote:   \nVelocity is defined as the distance trave lled in a given direction in a given amount \nof time. Displacement is the distance travel led in a specified direction.  \nAs a result, velocity can be defined as the rate at which displacement changes.",
  "Motion.txt\nUniform Velocity an d Non -Uniform Velocity  \nAssume that two athletes, Ram and Shyam, are running at a constant speed of 5 \nm/s. Ram moves in a straight line, while Shyam follows a circular path. For a \nlayperson, both Ram and Shyam are moving with uniform velocity, but for a \nphysicist, only Ram is running with uniform velocity because his speed and \ndirection of motion do not change.  \nIn the case of Shyam, who is running on a circular track, the direction of motion \nchanges at every instant because a circle is a polygon with infin ite sides, and \nShyam must change his direction at every instant.",
  "Motion.txt\nClass IX  Science                                                                                             15 \nA body is said to be moving with uniform velocity if it travels the same distance in \nthe same amount of time in the same direction.  \nA body is said to be moving with variable velocity if it co vers unequal distances in \nequal intervals of time and vice versa in a specified direction, or if its direction of \nmotion changes.",
  "Motion.txt\nAcceleration  \nWe are all aware that a car moving down the road does not have a uniform \nvelocity. Either the speed or the direc tion of travel shifts. We say that a vehicle is \naccelerating when it is speeding up, i.e. when the speed increases.  \nLet us look at the change in velocity of a train traveling from Bangalore to Mysore \nto get an idea of acceleration. The train, which was ini tially at rest, begins to move; \nits velocity gradually increases until it reaches a constant velocity after a certain \ntime interval. As the train approaches the next station, its speed gradually \ndecreases until it comes to a halt.  \nWhen a train starts from a stop, its speed increases from zero, and we say it is \naccelerating. After a while, the speed becomes uniform, and we say that the train is \nmoving at a uniform speed, which means that it is not accelerating. However, as \nthe train approaches Mysore, it slo ws down, indicating that the train is accelerating",
  "Motion.txt\nmoving at a uniform speed, which means that it is not accelerating. However, as \nthe train approaches Mysore, it slo ws down, indicating that the train is accelerating \nin the opposite direction. When the train comes to a halt in Mysore, it stops \naccelerating once more.  \nAs a result, it is clear that the term \"acceleration\" does not always imply that the \nspeed of a moving body increases; it can also decrease, remain constant, or become \nzero.  \nIn general, acceleration is defined as the rate at which the velocity of a moving \nbody changes over time.  \nThis change could be a change in the object's speed, direction of motion, or bo th. \nLet us now look up a mathematical formula for calculating acceleration.  \nIf an object moves with an initial velocity 'u' and reaches a final velocity 'v' in time \n't,' then the acceleration 'a' produced by the object is  \nAcceleration = Rate at which veloc ity changes over time.",
  "Motion.txt\nClass IX  Science                                                                                             16 \nvuat\uf02d\uf03d \nUnit of Acceleration:  \nThe SI unit of acceleration is m/s2 and it is a vector quantity.  \nDifferent Types of Acceleration   \nIt is clear from the preceding example that acceleration takes various forms \ndepending on the  change in velocity.  \nPositive acceleration:  \nWhen an object's velocity increases, it is said to be moving with positive \nacceleration.  \nPositive Acceleration   \n \nExample: a ball rolling downhill on an inclined plane.  \nNegative acceleration:  \nWhen an object's v elocity decreases, it is said to be moving with negative \nacceleration. Negative acceleration can also be referred to as retardation or \ndeceleration.  \nExample:  \n(1) a ball moving up an inclined plane.",
  "Motion.txt\nClass IX  Science                                                                                             17 \n(2) A vertically thrown upwards ball has a negative a cceleration as its velocity \ndecreases over time.  \n \n \nZero Acceleration   \nIf the change in velocity is zero, indicating that the object is either at rest or \nmoving at uniform velocity, the object is said to have zero acceleration.  \nA parked car, for example, or a train moving at a constant speed of 90 km/hr.  \n \nUniform Acceleration   \nThe object is said to be moving with uniform acceleration if the change in velocity \nat equal intervals of time is always the same.  \nAs an example, consider a body falling from a great  height towards the earth's \nsurface.  \n \nNon-uniform or Variable Acceleration   \nIf the change in velocity over equal time intervals is not the same, the object is said \nto be moving with variable acceleration.",
  "Motion.txt\nNon-uniform or Variable Acceleration   \nIf the change in velocity over equal time intervals is not the same, the object is said \nto be moving with variable acceleration.  \n \n \n \nClass IX  Science                                                                                             18 \nMotion   \nDistance -Time Table and Distance -Time Grap h  \nMr. X is taking a bus from New Delhi to Agra and recording his observations.  \nDistance in \nkm 0 10 20 30 40 50 60 \nTime  10.00 \nam 10.15 \nam 10.30 \nam 10:45 \nam 11:00 \nam 11:15 \nam 11:30 \nam \nAccording to the table above, the bus travels equal distances at equa l times. The \nbus is moving at a constant speed. In such a case, we can compute the distance \ntraveled by the bus at any given point in time.",
  "The \nbus is moving at a constant speed. In such a case, we can compute the distance \ntraveled by the bus at any given point in time.  \nConsider an object moving from its initial position x i to its final position x f in time \nt at a uniform speed v.   \n total distance  uniform speed  time taken \uf03d\n \nfixxvt\uf02d\uf03d\n \n(1)fix x vt\uf02d\uf03d",
  "Motion.txt\nfixxvt\uf02d\uf03d\n \n(1)fix x vt\uf02d\uf03d\n \nThe relationship between distance, time, and average speed is given by equation \n(1). This relationship can be used to  generate distance -time tables as well as to \ndetermine the position of any moving object at any given time. However, it is a \ntime-consuming and tedious process, especially when we need to determine the \nposition after a long period of time or compare the mo tion of two objects. In such \ncases, graphs such as the distance -time graph can be useful. A distance -time graph \nis a line graph that shows how distance changes over time. A distance -time graph \nplots time along the x -axis and distance along the y -axis.  \n \nDistance -Time Graph for Non - Uniform Motion",
  "Motion.txt\nDistance -Time Graph for Non - Uniform Motion    \n \nClass IX  Science                                                                                             19 \nLet us now look at the nature of a distance -time graph for a non -uniform motion. \nThe distance traveled by a bus every 15 minutes is shown in the table below.  \nDistance covered in km  0 5 15 20 25 30 35 \nTime in min utes 0 15 30 45 60 75 90 \nWe can deduce from the above table that the motion is non -uniform, i.e. it covers \nunequal distances in equal time intervals.  \n\u2022 Measure time along the x -axis and distance along the y -axis. \n \n\u2022 Analyze the provided data and select  the appropriate scale for time and distance.  \n \n \nClass IX  Science                                                                                             20 \n \n\u2022 Plot the points.  \n \n\u2022 join the points.",
  "Motion.txt\nClass IX  Science                                                                                             20 \n \n\u2022 Plot the points.  \n \n\u2022 join the points.  \n \n \nClass IX  Science                                                                                             21 \n \n \n\u2022 Consider any two points (A, B) on the graph.  \n \n \n \nClass IX  Science                                                                                             22 \n\u2022 Draw perpendicular from A to B to x and y axes.  \n \nJoin A to C to get a right angled ACB.  \n \nThe slope of the graph is shown below.  \n \n \nClass IX  Science                                                                                             23 \nBCABAC &\uf03d \nS\nt\uf03d\n \nspeed\uf03d\n \n \n\u2022 Write the title and scale chosen for the graph.  \n15 5 speed 30 15\uf02d\uf03d\uf02d\n \n10\n15\uf03d\n \n2\n3\uf03d\n \n0.666\u00a0 km / min\uf03d",
  "Motion.txt\nspeed\uf03d\n \n \n\u2022 Write the title and scale chosen for the graph.  \n15 5 speed 30 15\uf02d\uf03d\uf02d\n \n10\n15\uf03d\n \n2\n3\uf03d\n \n0.666\u00a0 km / min\uf03d\n \n \n \nClass IX  Science                                                                                             24 \n \n\u2022 Consider another two points on the graph, P and Q, and draw a right -angled \ntriangle PRQ.  \n \n slope  speed \uf03d\n \nQRPQPR\uf03d\n \n \n \nClass IX  Science                                                                                             25 \n35 30\n90 75\uf02d\uf03d\uf02d \n5\n15\uf03d\n \n0.333Km / min\uf03d\n \n \n\u2022 Complete Graph  \n \n \n \n \nClass IX  Science                                                                                             26 \nNature of S - t Graph for Non - Uniform Motion and Uses of Graphs  \nLet us now see the nature of S -t graph for non -uniform motion.   \n \n \n \nNature of s -t Graph for Non -Uniform Motion",
  "Motion.txt\nNature of s -t Graph for Non -Uniform Motion   \n \n \nClass IX  Science                                                                                             27 \nFigure (a) depicts the S -t graph as  the speed of a moving object increases, while \nFigure (b) depicts the S -t graph as the speed of a moving object decreases. The \nnature of the S -t graph allows us to determine whether the object is moving at a \nconstant or variable speed.  \nUses of Graphical R epresentation   \n\u2022 Because it provides a visual representation of two quantities, graphical \nrepresentation is more informative than tables (e.g., distance vs. time)  \n\u2022 A graph provides more information than a table at a glance. Both of the graphs \nshown here depict increasing speed.  \n \nFigure (1) depicts the nature of the variation in speed, indicating that the increase is \ngreater in the beginning up to time t 1 and relatively lower after t 2.",
  "Motion.txt\nFigure (1) depicts the nature of the variation in speed, indicating that the increase is \ngreater in the beginning up to time t 1 and relatively lower after t 2. \n \n \nClass IX  Science                                                                                             28 \n \nSimilarly, fig (2) depicts how the increase in speed becomes gre ater after t1. A \nsimilar explanation applies to the decreasing speed.  \n\u2022 Graphs are simple to read at a glance.  \n\u2022 Graph plotting takes less time and is more convenient.  \n\u2022 Graphs can be used to determine the position of any moving object at any point in \ntime. \n\u2022 Two moving objects' motions can be easily compared.  \n\u2022 Graphs reveal information about the nature of motion.  \n \nMotion   \nVelocity -Time Graph   \nThe variation of velocity with time can be graphically represented to calculate \nacceleration in the same way that we calculated speed from the distance -time \ngraph.",
  "Motion.txt\nClass IX  Science                                                                                             29 \nLet us now create a velocity -time(v -t) graph using the data below.  \nVelocity in m/s  0 10 20 30 40 50 \nTime in seconds  0 2 4 6 8 10 \n\u2022 Draw time on the x -axis and velocity on the y -axis.  \n\u2022 Analyze the provi ded data and select the appropriate scale for the x and y axes.  \n \n\u2022 Plot the given points.  \n \n \nClass IX  Science                                                                                             30 \n \n\u2022 Join the points  \n \n\u2022 Consider any two points A and B on the straight -line graph.  \n \n \nClass IX  Science                                                                                             31 \n \n\u2022 Draw perpendiculars from A and B to x and y -axes.  \n \n\u2022 Join A to C, ACB forms a right -angled triangle.",
  "Motion.txt\n\u2022 Draw perpendiculars from A and B to x and y -axes.  \n \n\u2022 Join A to C, ACB forms a right -angled triangle.  \n \n \nClass IX  Science                                                                                             32 \n \n\u2022 Slope of the graph  \nBC  Change in velocity AB  acceleration AC  time \uf03d \uf03d \uf03d\n \nCalculations:  \n30 20 Acceleration 64\uf02d\uf03d\uf02d\n \n10\n2\uf03d\n \n25\u00a0 m / s\uf03d\n \n \n \nClass IX  Science                                                                                             33 \n \n\u2022 Write the title for the graph.  \n \n\u2022 Complete Graph  \n \n \nClass IX  Science                                                                                             34 \n \nV - T Graph  \nLet us now examine the nature of the v - t graph for various types of motion.  \na) Increasing acceleration:  \nUniform acceleration  \n \nNon-uniform acceleration",
  "Motion.txt\nV - T Graph  \nLet us now examine the nature of the v - t graph for various types of motion.  \na) Increasing acceleration:  \nUniform acceleration  \n \nNon-uniform acceleration  \n \n \n \nClass IX  Science                                                                                             35 \n(b) Decreasing acceleration:  \nNon-uniform retardation  \n \nUniform retardation  \n \nZero acceleration  \n \n \nUses of Velocity -time Graphs   \nThe velocity -time graph can be used to derive the following results.   \n\u2022 The acceleration produced in a body.   \n\u2022 The distan ce traveled by a moving object.   \n\u2022 The equations of motion.  \n \n \nClass IX  Science                                                                                             36 \nSpeed - Time Graph  \nTo compute the distance traveled by a moving object using a speed -time graph.   \nThe graph below depicts the speed -time graph of a car traveling at a constant speed \nof 60 km/h fo r 5 hours .",
  "Motion.txt\nSpeed -Time Graph of a Car Moving with Uniform Speed   \nDistance travelled by the car   \n( )S v t\uf03d\uf0b4\n \n60 5\uf03d\uf0b4\n \n300\u00a0 km\uf03d\n \nBut \n60\u00a0 km / h OC\uf03d\uf03d Breadth of a reactangle  \nOABC  \n5h OA\uf03d\uf03d\nlength of a reactangle  OAB C\ni.e.,the distance covered by the car = l ength breadth\uf0b4\n300\u00a0 km\uf03d\n. \nTo calculate the distance traveled by a moving object using a speed -time graph, \nfind the area enclosed by the speed -time graph and the time axis. In the case of \nnon-uniform motion, the distance covered by the object increases in steps as the \nobject's speed increases. During the time intervals \n1 1 2 2 30 , , ,t t t t t\uf02d \uf02d \uf02d \uf0bc\uf0bc , the speed \nremains co nstant. \nThe motion of an object moving at a variable speed is depicted in the figure \nbelow.",
  "The motion of an object moving at a variable speed is depicted in the figure \nbelow. \n \n \nClass IX  Science                                                                                             37 \n \nSpeed - Time Graph for an Object Moving with Variable Speed",
  "Motion.txt\nClass IX  Science                                                                                             37 \n \nSpeed - Time Graph for an Object Moving with Variable Speed  \n \nCalculation of Distance:  \nThe object's total distance traveled during the time interval.   \n0- t6 = Area of rectangle 1 + area of rectangle 2 + \u2026\u2026 + area of rectangle 6.",
  "Motion.txt\nClass IX  Science                                                                                             38 \nMotion   \nEquations of Motion   \nTime, speed, distance covered, and acceleration are the variables in a uniformly \naccelerated rectilinear motion. These quantities have simple relationships . These \nrelationships are expressed using equations known as equations of motion.   \nThe equations of motion are:   \n(1) \nv u at\uf03d\uf02b  \n(2) \n21/ 2 S ut at\uf03d\uf02b  \n(3) \n222 v u aS\uf02d\uf03d  \nDerivation of the First Equation of Motion  \nConsider a particle moving in a stra ight line with a constant acceleration 'a.' Let \nthe particle be at \nA  at \n0t\uf03d , and \nu  be its initial velocity, and \nv  be its final \nvelocity at \ntt\uf03d .",
  "Let \nthe particle be at \nA  at \n0t\uf03d , and \nu  be its initial velocity, and \nv  be its final \nvelocity at \ntt\uf03d . \ntime \nvuat\uf02d\uf03d  \nv u at\uf02d\uf03d  \nv u at\uf03d\uf02b  \nI equation of motion  \nSecond Equation of Motion  \n total distance travelled  Average velocity  total time taken \uf03d\n \n(1)S\nt\uf03d \uf0bc\uf0bc\n \nAverage velocity can alsobe written as  \n(2)2uv\uf02b",
  "Motion.txt\n(1)S\nt\uf03d \uf0bc\uf0bc\n \nAverage velocity can alsobe written as  \n(2)2uv\uf02b\n  \n \nClass IX  Science                                                                                             39 \nFrom equation (1) and (2),  \n(3)2S u v\nt\uf02b\uf03d\n \nThe first equation of motion is \nv u at\uf03d\uf02b . Substituting the value of \nv  in equation \n(3),",
  "Substituting the value of \nv  in equation \n(3), we get  \n()\n22S u u at u u at t\nt\uf02b \uf02b \uf02b \uf02b\uf03d\uf03d\n \n(2 )\n2u at t\uf02b\uf03d\n \n21\n2S ut at\uf03d\uf02b\n \nII equation of motion  \nThird Equation o f Motion  \nThe first equation of motion is  \nv u at\uf03d\uf02b\n \n(1) v u at\uf02d \uf03d \uf0bc\n \nAverage velocity \n(2)S\nt\uf03d\n  \nAverage velocity \n(3)uv\nt\uf02b\uf03d\uf0d7\n  \nFrom equation (2) and equation (3) we get,  \n(4)u v S\ntt\uf02b\uf03d\uf0bc\n  \n \nClass IX  Science                                                                                             40 \nMultiplying equation (1) and equation (4) we get,",
  "(4)u v S\ntt\uf02b\uf03d\uf0bc\n  \n \nClass IX  Science                                                                                             40 \nMultiplying equation (1) and equation (4) we get,  \n2( )( )Sv u v u att\uf02d \uf02b \uf03d \uf0b4\n \n( )( ) 2v u v u aS\uf02d \uf02b \uf03d\n \n\uf028\uf029222 v u aS\uf02d\uf03d",
  "Motion.txt\n( )( ) 2v u v u aS\uf02d \uf02b \uf03d\n \n\uf028\uf029222 v u aS\uf02d\uf03d\n \n \nIII  Equation of motion  \nDerivations of Equations of Motion (Graphically)   \nFirst Equation of Motion  \n \nConsider an o bject moving in a straight line with a uniform velocity u. When its \ninitial velocity is u, give it a uniform acceleration an at time t = 0. The object's \nvelocity increases as a result of the acceleration to v (final velocity) in time t, and S \nis the distan ce covered by the object in time t.  \nThe graph depicts the velocity -time graph of the object's motion.  \nThe acceleration of a moving object is given by the slope of the  v - t graph.  \nThus, acceleration = slope  \n \n \nClass IX  Science                                                                                             41 \nBCABAC 0vu\nt\uf02d\uf03d\uf03d\uf02d \nvuat\uf02d\uf03d\n \nv u at\uf02d\uf03d\n \nv u at\uf03d\uf02b",
  "Motion.txt\nClass IX  Science                                                                                             41 \nBCABAC 0vu\nt\uf02d\uf03d\uf03d\uf02d \nvuat\uf02d\uf03d\n \nv u at\uf02d\uf03d\n \nv u at\uf03d\uf02b\n \n \nI equation of motion  \nSecond Equation of Motion   \nLet u be an object's initial velocity and 'a' be the acceleration produced in the body.",
  "The area enclosed by the velocity -time graph for the time interval 0 to t gives the \ndistance travelled S in time t.  \n \nGraphical Derivation of Second Equation  \nDistance travelled S = area of the trapezium ABDO  \n1OD OA BC AC2\uf03d \uf0b4 \uf02b \uf0b4\n \n1t u (v u) t2\uf03d \uf0b4 \uf02b \uf02d \uf0b4\n \n1ut ( )2v u t\uf03d \uf02b \uf02d \uf0b4\n \n \n \nClass IX  Science                                                                                             42 \nv u at\uf03d\uf02b\n\u2223\nv u at\uf02d\uf03d \n1\n2S ut at t\uf03d \uf02b \uf0b4\n \n21\n2ut at\uf03d\uf02b\n \nII equation of motion",
  "Motion.txt\n21\n2ut at\uf03d\uf02b\n \nII equation of motion  \n \nThird Equation of Motion   \nLet 'u' be an object's initial velocity and a be the acceleration produced in the body. \nThe area enclosed by the v - t graph gives the distance travelled ' S' in time 't'.",
  "The area enclosed by the v - t graph gives the distance travelled ' S' in time 't'.  \n \nGraphical Derivation of Third Equation  \nS\uf03d\n area of trapezium \nOABD  \n\uf028\uf029121\n2b b h\uf03d\uf02b\n \n1(OA BD)AC2\uf03d\uf02b\n \n1( ) (1)2u v t\uf03d\uf02b\n \nBut we know that \nvuat\uf02d\uf03d  or \nvuta\uf02d\uf03d  \n \n \nClass IX  Science                                                                                             43 \nSubstituting the value of \nt  in equation (1) we get,  \n1 ( )( )\n2u v v uSa\uf02b\uf02d\uf03d\n \n1 ( )( )\n2v u v u\na\uf02b\uf02d\uf03d\n \n2 ( )( )as v u v u\uf03d \uf02b \uf02d\n \n( )( ) 2v u v u as\uf02b \uf02d \uf03d\n \n222 v u as\uf02d\uf03d",
  "Motion.txt\n1 ( )( )\n2v u v u\na\uf02b\uf02d\uf03d\n \n2 ( )( )as v u v u\uf03d \uf02b \uf02d\n \n( )( ) 2v u v u as\uf02b \uf02d \uf03d\n \n222 v u as\uf02d\uf03d\n \n \nIII Equation of Motion   \nCircular Motion   \nWe classified motion along a circular track as non -uniform motion in the example \ndiscussed under the topic uniform and non -uniform motion. Let's take a look at \nwhy circular motion is considered non -uniform motion. The figure depicts an \nathlete runn ing at a constant speed on a hexagonal track.  \n \nAthlete Running on a Regular Hexagonal Track   \nThe athlete runs at a constant speed along the track segments AB, BC, CD, DE, \nEF, and FA, and at the turns, he quickly changes direction to stay on the track \nwithout changing his speed. Similarly, if the track had been a regular octagon, the \nathlete would have had to change directions eight times in order to stay on the \ntrack",
  "Motion.txt\nClass IX  Science                                                                                             44 \n.  \nAthlete Running on a Regular Octagonal Track   \nThe athlete must turn more frequently a s the number of sides of the track increases. \nIf we increase the number of sides indefinitely, the track will take on the shape of a \ncircle. As a result, because a circle is a polygon with infinite sides, motion along a \ncircular path is classified as non -uniform motion.  \n \nAthlete Running on a Circular Track   \nThus, an object moving at uniform speed along a circular track is an example of \nnon-uniform motion because the object's direction of motion changes at every \ninstant of time.   \n \nExamples of Uniform Circ ular Motion   \n(1) A car negotiating a curve at a constant speed.  \n \n \nClass IX  Science                                                                                             45",
  "Motion.txt\nClass IX  Science                                                                                             45 \n \n(2) An athlete spinning a hammer in a circle before throwing it.  \n \n(3) An aircraft looping the loop.   \n \n \nExpression for Linear Velocity  \nIf an athlete takes t seconds to complete one circ ular path of radius r, then the \nvelocity v is given by the relation,  \n \n \nClass IX  Science                                                                                             46 \n distance travelled v time \uf03d \nDistance travelled = Circumference of a circle  \n2r\uf070\uf03d\n \nLinear Velocity\n 2r \nt\uf03d",
  "Gravitation.txt\nClass IX Science    1 \nRevision Notes \nClass 9  Science Chapter 9 - \nGravitation \n\u2022 Toss a stone from a great height. What are your observations?\n\u2022 The stone, which was at first at rest, begins to move towards the ground\nand reaches its maximum speed right before it meets it.\n\u2022 The stone is not travelling at a constant rate. Its speed fluctuates at all\ntimes, indicating that the stone is accelerating.\n\u2022 A force  is necessary to cause an acceleration in a body, according to\nNewton's second law of motion .\n\u2022 The stone was not pushed or pulled in any way. What was the source of\nthe force?\n\u2022 Sir Isaac Newton  came up with the solution to this dilemma after seeing\nan apple fall from a tree.\n\u2022 His thesis was that the apple is attracted to the Earth, and the Earth is\nattracted to the apple The Earth's force on the apple is enormous, and as a\nresult, the apple arrives on Earth.\n\u2022 The apple, on the other hand, is unable t o draw the Earth since the force it",
  "Gravitation.txt\nattracted to the apple The Earth's force on the apple is enormous, and as a\nresult, the apple arrives on Earth.\n\u2022 The apple, on the other hand, is unable t o draw the Earth since the force it\nexerts on it is insignificant.\n\u2022 As a result, we can deduce that the acceleration caused by Earth's immense\nforce of attraction is the cause of the stone's acceleration.\n\u2022 It is evident from the preceding example that this force of attraction ties\nClass IX Science    2",
  "Gravitation.txt\nour complicated universe together, keeps the moon revolving around the  \nEarth, keeps all of the planets in their orbits around the Sun, and helps us  \nwalk correctly on the Earth's surface.  \n\u2022 The force of gr avitation , or gravitation , is a form of attraction that  \nexists between any two objects in the universe.  \n\u2022 The force of gravity  or gravity  is the attraction or gravitational force  \nbetween Earth  (or any planet) and any other material objects in the  \ncosmos.",
  "Gravitation.txt\nThe Universal Law of Gravitation or Newton's Law of Gravitation : \n\u2022 The universal law of gravitation  is a mathematical relationship that Sir \nIsaac Newton  proposed to measure the gravitational force . \n\u2022 According to this law \u201c Every particle in the universe attracts every  \nother particle with a force which is directly proportional to the  \nproduct of their masses and inversely proportional to the square of  \nthe distance between them, the direction of the force being along the  \nline joining the masses \u201d. \n\u2022 Consider two mass \n1m and \n2m  objects separated by a distance  \nd . The  \ngravitational force  \nF is proportional  to the product of the masses , \naccording to Newton's law . \n()12 F  m m    ...... 1\uf0b5\n \nand inversely proportional to the square of the distance between the  \nmasses\n()21F         ...... 2d\uf0b5",
  "Gravitation.txt\nand inversely proportional to the square of the distance between the  \nmasses\n()21F         ...... 2d\uf0b5\n  \n \n \n \n \n \n \n \n \n \n \nTwo Objects of Masses \n1m  and \n2m  separated by a distance \nd . \nInversely proportional is always represented as directly proportional to the  \nreciprocal of that quantity.  \nCombining equation \n()1  and equation  \n()2 , we get  \nClass IX Science    3 \n \n \n \n \n \n()12\n2\n12\n2mmF  d\nGm mF      ....... 3d\uf0b5\n\uf0b5\n \nWhere \nG  is a proportionality constant  known as the universal  \ngravitational constant .  \nG\n is known as the universal constant because its value remains constant  \nthroughout the cosmos and is unaffected by object masses.  \n \nUniversal Gravitational Constant : \n\u2022 The mathematical form  of Newton's Law of Gravitation  is \n12\n2Gm mF = d\n \n If \n12m  = m 1=  , and \nd = 1  , then  \n2G \u00d71\u00d71F = 1\nF = G",
  "Gravitation.txt\nUniversal Gravitational Constant : \n\u2022 The mathematical form  of Newton's Law of Gravitation  is \n12\n2Gm mF = d\n \n If \n12m  = m 1=  , and \nd = 1  , then  \n2G \u00d71\u00d71F = 1\nF = G\n \n\u2022 As a result, the universal gravitational constant  can be defined as the  \ngravitational force  that exists between two unit masses separated by a  \nunit distance.  \n \n\u2022 \nSI unit of gravitational constant : \n2\n12FdG = mm\n \nSI\n Unit of force \nF  is \nN, \nSI unit of distance is metres and that of mass is  \nkg\n. \nSI\n Unit of \n2NmG = kg kg\uf0b4  \nSI\n Unit of \n2\n2mG = Nkg  or \n22Nm kg\u2212  \nThe experimental value  of \nG  equal to \n2\n11\n2Nm6.6734 10  kg\uf0b4  was measured  \nby Sir Henry Cavendish  in \n1798  .",
  "Class IX Science    4 \n \n \n \n \n \nDependence of Gravitational Force on Mass:  \nThe force of attraction  is directly proportional to the mass of the body, \naccording to Newton's law of gravitation . \n \n1. Two objects of mass \nm separated by a distance \nd :",
  "Gravitation.txt\n1. Two objects of mass \nm separated by a distance \nd : \n \n \n \n \n \n \n \n \nIf two objects of mass \nm  are separated by a distance \nd , the force between  \nthem is given by the relation are as follows;  \n1 2\n2\n2GmmF  = d\nGm    = d\n \n \n2. Two objects of mass \nm and \n2m  separated by a distance \nd\n : \n \n \n \n \n \n \n \n \n \n \nWhen the mass of one of the two objects is doubled , force of attraction  \nis given by the relation are as follows;  \n2\n2 2\n2\n2\n1Gm mF  = d\n2Gm    = d\n    = 2F\n \n \nClass IX Science    5 \n \n \n \n \n \n \n3.",
  "Two objects of mass \n2m  separated by a distance \nd : \n \n \n \n \n \n \n \n \n \nWhen the masses of both bodies are doub led, the force of attraction is \ngiven as;  \n22\n3 2\n2\n2\n1G m mF  = d\n4Gm    = d\n    = 4F\n \nThat is whenever the mass increases the force of attraction also  \nincreases .",
  "Gravitation.txt\nThat is whenever the mass increases the force of attraction also  \nincreases . \n \nDependence of Gravitational Force on Distance:  \nThe force of attraction between two bodies is inversely proportional to the \nsquare of their distance , according to the universal law of gravitation.  \n \n1. Force of attract ion between two bodies of mass \nm  separated by a  \ndistance \nd  : \n \n \n \n \n \n \n \n \n \n \nClass IX Science    6 \n \n \n \n \n \n12\n1 2\n2\n2Gm mF  = d\nGm    = d\n \nHere, two bodies of mass \nm  are separated by a distance \nd  and hence,  \n2\n1 2GmF  = d\n \n \n2. The force of attraction when the distance is doubled:  \n \n \n \n \n \n \n \n \n \n()2 2\n2\n2GmmF  = \n2d\nGm    = 4d\n \nHere, two bodies of mass \nm  are separated by a distance \n2d  and therefore,  \n2\n2 2\n211 GmF  = 4d\n1F  = F4\n \n \n3.",
  "Force of attraction when the distance between the bodies is increased  \nthree times:  \n \n \n \n \n \nClass IX Science    7",
  "Gravitation.txt\n3. Force of attraction when the distance between the bodies is increased  \nthree times:  \n \n \n \n \n \nClass IX Science    7 \n \n \n \n \n \n()3 2\n2\n2GmmF  = \n3d\nGm    = 9d \nHere, two bodies of mass \nm  are separated by a distance \n3d  and therefore,  \n2\n3 2\n311 GmF  = 9d\n1F  = F9\n \nIt results that  \na) When  the distance  is doubled , the force is decreased to \n1\n4  th of its  \noriginal value . \nb) If the distance  is extended three times , the force  is reduced to \n1\n9  th of  \nits original value.  \nc) We can conclude from the preceding example that the force of attraction  \nbetween the bodies varies inversely with the square of distance  \nbetween them.  \n \nGravitational Force between two Light Objects : \nLet us now calculate the force of gravitation existing between two unit masses \nseparated by a unit distance.",
  "Gravitational Force between two Light Objects : \nLet us now calculate the force of gravitation existing between two unit masses \nseparated by a unit distance.  \n1\n2\n2\n-11\n2m  = 1 kg\nm  = 1 kg\n   d = 1 m\nNm  G = 6.6734 10kg\uf0b4",
  "Gravitation.txt\nTherefore, force can be calculated as;  \n12\n2\n-11\n2\n-11Gm mF = d\n6.6734 10 \u00d71\u00d71F = 1\nF = 6.6734 10  N\uf0b4\n\uf0b4\n Class IX Science    8 \n \n \n \n \n \nThis is a very weak force.  \n \nTo find Force existing be tween two objects of masses \n60 kg  and \n100 kg  \nseparated by a distance of \n1 m  : \n \n12\n2\n-11\n2\n-8\n-8Gm mF = d\n6.6734 10 \u00d760\u00d7100F = 1\nF = 6.6734 10 6 \nF = 40.04 10  N\uf0b4\n\uf0b4\uf0b4\n\uf0b4\n \nThis is also a very weak force.  \nIt is clear from the preceding two examples why we do not feel the force \nproduced by one object (on the Earth's surface) on the other .",
  "Gravitation.txt\nThis is also a very weak force.  \nIt is clear from the preceding two examples why we do not feel the force \nproduced by one object (on the Earth's surface) on the other . \n \nGravitational Force between Massive Objects:  \nLet's calculate the for ce of attraction between a \n50 kg  object and the Earth. The \nEarth's mass is approximately \n246 10  kg\uf0b4 . The Earth's distance from the object \nis roughly \n564 10  m\uf0b4 .",
  "The \nEarth's mass is approximately \n246 10  kg\uf0b4 . The Earth's distance from the object \nis roughly \n564 10  m\uf0b4 .  \nThe force of attraction between the object and the Earth  is, \n()\n()12\n2\n-11 24\n25\n11 25\n2 10\n11 25 10Gm mF = d\n6.6734 10 \u00d76 10 \u00d750   = \n64 10\n6.6734\u00d76\u00d75 10 10   = \n64 10\n6.6734\u00d76\u00d75 10 10 10   = 64 64\u2212\n\u2212\u2212\uf0b4\uf0b4\n\uf0b4\n\uf0b4\uf0b4\n\uf0b4\n\uf0b4 \uf0b4 \uf0b4\n\uf0b4\n \nTherefore,  \n4\n56.6734\u00d76\u00d75 10F = 64 64\n6.6734\u00d73 10   = 64 64\nF = 488.7 N\uf0b4\n\uf0b4\n\uf0b4\n\uf0b4\n \nThis force is strong, we cannot ignore it.  Class IX Science    9",
  "Gravitation.txt\nTherefore,  \n4\n56.6734\u00d76\u00d75 10F = 64 64\n6.6734\u00d73 10   = 64 64\nF = 488.7 N\uf0b4\n\uf0b4\n\uf0b4\n\uf0b4\n \nThis force is strong, we cannot ignore it.  Class IX Science    9 \n \n \n \n \n \nNow let us calculate the force of attraction between Earth and the Sun.",
  "Class IX Science    9 \n \n \n \n \n \nNow let us calculate the force of attraction between Earth and the Sun. T he mass \nof the Earth \n24= 6 10  kg\uf0b4  \nThe mass of the Sun \n30= 1.99 10  kg\uf0b4  \nThe distance between the Earth and the Sun \n10= 15 10  m\uf0b4  \nTherefore,  \n()12\n2\n-11 24 30\n210\n11 24 30 20Gm mF = d\n6.6734 10 \u00d76 10 \u00d71.99 10   = \n15 10\n6.6734\u00d76\u00d71.99 10 10 10 10   = 225\u2212\u2212\uf0b4 \uf0b4 \uf0b4\n\uf0b4\n\uf0b4 \uf0b4 \uf0b4 \uf0b4\n \nHence,  \n23\n226.6734\u00d76\u00d71.99 10F = 225\nF = 3.541\u00d710  N\uf0b4\n \nThis force is very large and it is this f orce which keeps the planets in their \nrespective orbits.",
  "Conclusion:   \nWhen two objects of ordinary size are considered, the gravitational force is quite \ntiny, but when at least one of the items is huge, the force is very large.",
  "Gravitation.txt\nConclusion:   \nWhen two objects of ordinary size are considered, the gravitational force is quite \ntiny, but when at least one of the items is huge, the force is very large.  \n \nCentre of Gravity : \n\u2022 Every particle is drawn to the centre of the earth, as we all know. A body  \nis made up of number of particles. Because the body is small in  \ncomparison to the earth, the gravitational attraction acting on these  \nparticles can be considered parallel to one ano ther, as illustrated in the  \ndiagram.  \n \n \nClass IX Science    10",
  "Gravitation.txt\nClass IX Science    10 \n \n \n \n \n \n\u2022 A single force acting vertically in the downward direction can be  \nreplaced by a single force acting through a fixed location called the  \nbody's centre of gravity .  \n\u2022 The resulting force is equivalent to the body's weight.  \n\u2022 As a result , the centre of gravity is the point through which the body's  \nweight acts regardless of its position.   \n\u2022 For bodies which are of regular shape and which have uniform density , \nthe centre of gravity lies at the geometrical centre of t he body.  \n\u2022 The geometrical centre of gravity of bodies of regular shape and  \nuniform density is located at the geometrical centre of the body.",
  "Gravitation.txt\nApplication of Newton's Law of Gravitation : \n\u2022 One of the important applications of Newton's law is to estimate masses  \nof binary stars . A binary star is a system of two stars orbiting round their  \ncommon centre of mass.  \n\u2022 Any irregularity in the motion  of a star indicates that it might be another  \nstar or a planet going round the stars. This regularity in the motion of a  \nstar is called a wobble.",
  "Gravitation.txt\nMass and Weight : \n\u2022 Mass and weight are sometimes confused, yet they are two distinct  \nnumbers. Let's try to figure out what makes them different.  \n\u2022 Mass of a body is defined as the amount of matter contained in it.   \n\u2022 The kilogramme  is the \nSI  unit of mass  \n()kg .  \n\u2022 Mass is a scalar quantity .  \n\u2022 The amount of matter contained in a body does not vary with time or  \nlocation, i.e., the mass of a body remains constant throughout the cosmos.  \nHowever, the masses of two bodies might differ significantly.  \n\u2022 A pan balance  is used to determine a person's mass.  \n\u2022 Weight is defined as the force with which an object is pulled towards  \nthe centre of the Earth.  \n\u2022 \nWeight of a body = force exerted by the Earth = mg  (according to  \n\u2022 Newton's second law of motion)  \n\u2022 \nW = mg  \nSI\n unit of weight  is Newton . \nFor example,  the weight  of a body  having  a mass  of \n1kg  is  Class IX Science    11",
  "Gravitation.txt\nW = mg\nW = 1 9.8\nW = 9.8 N\uf0b4 \n\u2022 We know  that \nkg wt  is commonly  used as  the unit of weight . \n\u2022 \n1kg weight is the force with which an object of mass \n1kg  is pulled  \ntowards the Earth.  \nW = mg\n \n1 kg wt = 1 9.8\n1 kg wt = 9.8 N\uf0b4\n \n\u2022 Spring balance  is used to determine weight.  \n\u2022 Weight fluctuates from location to place because it is affected by gravity's  \nacceleration.  \n\u2022 At the poles, a body weighs more than in the equator , and at the centre  \nof the Earth, a body's weight becomes zero  because gravity's  \nacceleration is zero",
  "Gravitation.txt\nDifference between Mass and Weight : \nMass  Weight  \nIt is the amount  of matter  contained  \nin an object  It is the force  with which  an object  \nis pulled  towards  the Earth  \nThe mass  of a body  is constant  \nthroughout the  universe  Weight  varies  from  place  to place  \nas \ng varies  \nMass  can never  be equal  to zero  Weight  can be equal  to zero  \nMass is  a scalar quantity  Weight  is a vector  quantity  \nSI\n unit of mass  is \nkg \nSI  unit of weight  is \nNewton  \n \nTo show that  weight of a body on moon is \n1\n6  th its weight on Earth : \n\u2022 Let \nm  be the mass of a body on Earth.",
  "Its weight on Earth is given by the  \nequation is as follows;  \n()ee\ne\ne 2\neW  = mg\nmGMW  =      ---- 1R\n \nSince,  Class IX Science    12 \n \n \n \n \n \ne\ne 2\neGMg  = R\uf0e9\uf0f9\n\uf0ea\uf0fa\uf0eb\uf0fb \nThe weig ht of the same body on moon \n()Wm  is given by,  \n()mm\nm\nm 2\nmW  = mg\nmGMW  =      ---- 2R\n \nSince,  \nm\nm 2\nmGMg  = R\uf0e9\uf0f9\n\uf0ea\uf0fa\uf0eb\uf0fb",
  "Gravitation.txt\ne\ne 2\neGMg  = R\uf0e9\uf0f9\n\uf0ea\uf0fa\uf0eb\uf0fb \nThe weig ht of the same body on moon \n()Wm  is given by,  \n()mm\nm\nm 2\nmW  = mg\nmGMW  =      ---- 2R\n \nSince,  \nm\nm 2\nmGMg  = R\uf0e9\uf0f9\n\uf0ea\uf0fa\uf0eb\uf0fb\n \nBy dividing equation \n()2  by equation \n()1  we get,  \n()2\nm m e\n2\ne m e\n2\nm m e\n2\ne m e\n2\nm m e\ne e mW mGM R = W R mGM\nW M R =W R M\nW M R =       ---- 3W M R\uf0b4\n\uf0e6\uf0f6\uf0e6\uf0f6\n\uf0e7\uf0f7\uf0e7\uf0f7\uf0e8\uf0f8\uf0e8\uf0f8\n \nBut we know that ,",
  "emM  = 100M  and \nemR  = 4R  , therefore  \nm\ne\ne\nmM1 = M 100\nR = 4 R\n \nBy substituting above values in equation \n()3 , we get  \n()2m\ne\nm\ne\nm\ne\nm\neW1 = 4W 100\nW 16 =W 100\nW1 =W 6.25\nW1 =W6\uf0e6\uf0f6\n\uf0e7\uf0f7\uf0e8\uf0f8\n \nme1W  = W6\n Class IX Science    13 \n \n \n \n \n \nThat is the weight of a body on moon is \n1\n6  th its weight on Earth .",
  "Gravitation.txt\nme1W  = W6\n Class IX Science    13 \n \n \n \n \n \nThat is the weight of a body on moon is \n1\n6  th its weight on Earth . \n \nWeightlessness : \n\u2022 We frequently hear that astronauts in space experience weightlessness.  \nWhat exactly does this imply?  \n\u2022 Let us show weightlessness with a simple experiment. Suspend a stone  \nfrom a spring balance, and the weight of the stone is displayed on the  \nspring balance's pointer.  \n\u2022 Allow the stone, as well as the spring balance, to fall freely.  \n\u2022 The spring balance registers \n0  weight, showing that the stone is devoid of  \nweight.  \n\u2022 Does this imply that the stone has no weight?  \n\u2022 The stone, on the other hand, is in a state of weightlessness because it is  \nfalling freely.  \n\u2022 When the weight of one object is balanced against the weight o f another,  \nthe body becomes aware of its own weight.",
  "Gravitation.txt\n\u2022 Let us now attempt to explain why an astronaut in a spaceship feels  \nweightless.  \n\u2022 When an astronaut is orbiting the Earth in a spaceship, both the person  \nand the spaceship are in free fall towards the Earth.  \n\u2022 During a free fall, both go downhill with the same acceleration, which is  \nClass IX Science    14 \n \n \n \n \n \nequal to gravity's acceleration.  \n\u2022 As a result, the astronaut exerts no force on the spaceship's sides or floor,  \nand the spacesh ip's sides and floor do not push the astronaut up.  \n\u2022 As a result, the astronaut feels weightless while orbiting the Earth in a  \nspaceship .",
  "Gravitation.txt\nDensity:  \n\u2022 Cotton takes up m ore room than iron, hence \n0.5 kg  of cotton takes up  \nmore space than \n0.5 kg  of iron.  \n\u2022 Iron particles are tightly packed, whereas cotton particles are loosely  \npacked. There is more iron packed into a given volume.  \n\u2022 This explains why iron is heavier than cotton of the same volume.  \n\u2022 A substanc e's density is defined as the mass per unit volume of the  \nsubstance.  \n\u2022 \nMass of the substanceDensity = Volume of the substance  \nMD = v\n \nWhere, \nD  represents the density,  \nM mass and  \nv volume.  \nSI\n unit of density is \n3kg\nm  \n\u2022 When specific criteria are met, a substance's density remains constant.  \n\u2022 As a result, one of a material's distinguishing characteristics is its density,  \nwhich may be used to determine the purity of any substance.  \n \nClass IX Science    15",
  "Gravitation.txt\nRelative Density of a Substance : \n\u2022 We utilise the relation \nMD = v  to determine the density  of a substance or  \nan item by determining the mass and volume of the substance.  \n\u2022 Only if the thing has a regular shape is this possible.  \n\u2022 Measuring the size of an object with an irregular shape is difficult.  \n\u2022 In such instances, we express the object's density in terms of wate r density.  \n\u2022 The relative density of a substance is the ratio of its dens ity to the density  \nof water at \n4  degrees Celsius. The relative density of water is assumed to  \nbe one.  \n\u2022 What does it mean when someone says  gold's relative density is \n19.3  ? \n\u2022 It means that gold has \n19.3  times the density of water of the same volume.  \n\u2022 Objects with a relative density less than one float in water, while those  \nwith a density larger than one sink.  \n0Density of the substanceRelative density of a substance = Density of water at 4 C\nMass of the substance",
  "Gravitation.txt\nwith a density larger than one sink.  \n0Density of the substanceRelative density of a substance = Density of water at 4 C\nMass of the substance\nVolume of the substance                                                  = Mass of water\nVolu\uf0e6\uf0f6\uf0e7\uf0f7\uf0e8\uf0f8\nme of water\nMass of the substance Volume of water                                                  = \u00d7Volume of the substance Mass of water\uf0e6\uf0f6\uf0e7\uf0f7\uf0e8\uf0f8",
  "Gravitation.txt\n\u2022 Now, if we take equal amounts of the material and water, we get the  \nFollowing : \nMass of the substanceRelative density of a substance = Volume of an equal volume of water\n \n\u2022 The relative density has no unit because it is a ratio of two identical  \nquantities.  \n \nThrust and Pressure : \n\u2022 We defined force as an external agent that modifies the direction of  \nmotion, speed, or shape of the body at the start of this chapter.  \n\u2022 We were simply talking about the forces acting at a spot on a body the  \nwhole time.  \n\u2022 Consider the forces at wor k in a given location.  \n\u2022 If you want to hang a poster on your classroom bulletin board, you must  \napply force to the head of the drawing pin, which is perpendicular to the  \nsurface of the bulletin board.  Class IX Science    16 \n \n \n \n \n \n\u2022 This force, which is acting perpendicular to the surface, is referred to as  \nthrust.",
  "Gravitation.txt\n\u2022 This force, which is acting perpendicular to the surface, is referred to as  \nthrust.  \n \n \n\u2022 The force operating on a body perpendicular to its surface is known  \nas thrust.  \n\u2022 The Newton is the \nSI  unit of thrust \n()N  . \n\u2022 Let's see if there's a relationship between the applied force (thrust) and  \nthe region on which it acts . \n\u2022 Hold a pin erect in the middle of a stack of papers. Another pin should be  \nplaced next to it, upside down, with its flat head resting on the pile.  \n\u2022 Place  a flat object, such as a duster, on both of these pins to press them  \ndown. We notice that the erect pin pierces through the stack of papers.  \n \n\u2022 This is because the force operating on the erect pin is applied over a  \nlimited area, but the force acting on the second pin is applied over a broad  \narea.   \nClass IX Science    17",
  "Gravitation.txt\n\u2022 A thin yet durable string strap is used to hold your bag.  \n\u2022 Now, using a wide cloth band as a strap, raise the same bag. A school bag  \nwith a wide textile band is more comfortable to carry than one with a tiny  \nstrip.  \n\u2022 This is because the weight of the books is dispersed over a larger area of  \nthe shoulder in the second example, exerting less force.  \n\u2022 As can be seen from the examples above, the efficiency of the applied  \nforce is dependent on the region o n which it acts.  \n\u2022 There is now a requirement to define a new physical quantity known as  \npressure . \n\u2022 The force operating on a unit area is known as pressure  \nForcePressure = Area\nThrustPressure = Area\n \nThe \nSI  unit of pressure is \n2N\nm  . \n2N\nm\n is known as Pascal \n()Pa  in honor of the French Scientist Blaise  \nPascal.  \n2N1  = 1 Pascalm",
  "Gravitation.txt\nThe \nSI  unit of pressure is \n2N\nm  . \n2N\nm\n is known as Pascal \n()Pa  in honor of the French Scientist Blaise  \nPascal.  \n2N1  = 1 Pascalm\n \n\u2022 Because a kilopascal is a very small unit, we frequently utilise it.  \n\u2022 The force exerted and the area over which the force acts are the two  \nfactors that determine pressure.",
  "Gravitation.txt\n\u2022 Because a kilopascal is a very small unit, we frequently utilise it.  \n\u2022 The force exerted and the area over which the force acts are the two  \nfactors that determine pressure.  \n \nBuoyancy and Archimedes' Principle : \n\u2022 It is general knowledge that when bodies are submerged in water or any  \nother liquid, they appear lighter.  \n\u2022 While bathing, we notice that as soon as the mug of water rises over the  \nwater's surface, it becomes noticeably heavier.  \n\u2022 When a fish is taken out of the water, it looks to be heavier in the air  than \nit was in the water.  \n\u2022 Let's have a look at why that is.  \n\u2022 Because the liquid or water exerts an upward force on the items immersed  \nin it, they appear to be lighter in water or any other liquid.  \n\u2022 Let's see if there is an apparent loss of weight while im mersed in water by  \nconducting an experiment.  \n\u2022 Attach a stone to one of the spring balance's ends. Suspend the spring  Class IX Science    18",
  "Gravitation.txt\nbalance in the manner depicted in the diagram.  \n \n \n \nExperimental set up to Prove Archimedes' Principle : \n\u2022 Take note of the spring b alance reading. Let's call it \nW1  .  \n\u2022 Now carefully immerse the stone into a jar of water and record the reading  \non the spring balance.  \n\u2022 The spring balance's reading continues to drop until it is entirely  \nsubmerged in water.  \n\u2022 The weight of the stone is determined by the reading on the spring balance.  \n\u2022 We may deduce that the weight of the object is reducing as it is dropped  \nin water because the reading continues to decrease.  \n\u2022 The apparent weight loss indicate s that a force is working on the object in  \nan upward direction, causing it to lose weight.  \n\u2022 The buoyant force is the upward force exerted on an object immersed  \nin a liquid that causes the object to appear to lose weight.  \n\u2022 Buoyancy is defined as a liquid's te ndency to exert an upward force  \non an object placed in it, causing it to float or rise.",
  "Gravitation.txt\nFactors Affecting the Buoyant Force : \n\u2022 We know that an iron nail sinks when placed on the surface of water,  \nwhereas an iron ship floats. This is due to the ship's larger size or volume.  \n\u2022 When an iron nail and a cork of equal mass are placed in water, the iron  \nnail sinks because the density of the iron nail is greater than that of the  \nwater, whilst the density of the cork is lower.  \nClass IX Science    19 \n \n \n \n \n \n\u2022 When the density of the liquid excee ds the density of the body's material,  \nthe body floats due to the buoyant force  it exerts, and vice versa.  \n\u2022 The buoyant force experienced by a body while submerged in a liquid  \nis dependent on the volume of the body and the density of the liquid , \nas shown in  the examples above.",
  "Gravitation.txt\nArchimedes' Principle:  \n\u2022 Archimedes investigated the up thrust acting on a body when it is  \npartially or entirely submerged in a fluid, conducting various tests,  \nand finally stating the Archimedes' Principle.  \n\u2022 When a body is partially or completely immersed in a fluid, it feels an  \nup thrust (buoyant force) equal to the weight of the liquid displaced,  \naccording to this principle.",
  "Gravitation.txt\nExperiment to Verify Archimedes' Principle : \n\u2022 Using a physical  balance, determine the mass \n()m  of a clean and dry  \nbeaker.  \n\u2022 Suspend a stone from a spring balance to determine its weight. Fill a  \nEureka can (a beaker with a spout towards the top) with water until it  \nreaches the spout. Plac e the mass \nm  beaker under the spout.  \n\u2022 Gently lower the solid into the Eureka can, suspended from spring  \nbalance, until the stone is entirely immersed in water.  \n\u2022 When submerged in water, the stone displaces a particular amount of  \nwater.  \n\u2022 The spr ing balance registers a lower value, indicating that the solid is up \nthrust . The water that has been displaced is collected in the beaker.  \n\u2022 The mass of the water and beaker is calculated using the phys ical balance.  \nLet's call it \n1m .  \n\u2022 Therefore, \n1 Amount of water displaced = m - m  \n\u2022 When the apparent loss of weight of the solid in water is compared to the",
  "Gravitation.txt\nLet's call it \n1m .  \n\u2022 Therefore, \n1 Amount of water displaced = m - m  \n\u2022 When the apparent loss of weight of the solid in water is compared to the  \namount of water displaced, they are found to be equal. As a result, this  \nexperiment proves Archimedes' Principle.",
  "Gravitation.txt\nApplication of Archimedes' Principle : \n\u2022 It's employed in the construction of ships and submarines .  \n\u2022 This principle underpins lactometers and hydrometers , which are used  \nto determine the density of liquids  and measure the purity of a sample  \nof milk.",
  "The Fundamental Unit Of Life.txt\nRevision\nNotes\nfor\nClass\n9\nScience\nChapter\n5\n-\nThe\nFundamental\nUnit\nOf\nLife\nWhat\nare\nthe\nComponents\nof\nLiving\nOrganisms?\nCells\nare\nthe\nbuilding\nblocks\nof\nall\nliving\nbeings.\nComplex\norganisms'\nprimary\nstructural\nand\nfunctional\nunit\nis\nthe\ncell.\nHistory\nof\nCell:\n\u25cf\nCells\nwere\ndiscovered\nfor\nthe\nfirst\ntime\nin\n1665\nby\nRobert\nHooke\nusing\na\ncrude\nmicroscope.\n\u25cf\nWith\na\nbetter\nmicroscope,\nLeeuwenhoek\nobserved\nfree-living\ncells\nin\npond\nwater\nfor\nthe\nfirst\ntime\nin\n1674.",
  "\u25cf\nWith\na\nbetter\nmicroscope,\nLeeuwenhoek\nobserved\nfree-living\ncells\nin\npond\nwater\nfor\nthe\nfirst\ntime\nin\n1674.\n\u25cf\nThe\nnucleus\nof\nthe\ncell\nwas\nfound\nby\nRobert\nBrown\nin\n1831\n\u25cf\nPurkinje\ncreated\nthe\nname\n\"protoplasm\"\nfor\nthe\ncell's\nfluid\nportion\nin\n1839\n\u25cf\nThe\ncell\ntheory,\npresented\nby\nSchleiden\nin\n1838\nand\nSchwann\nin\n1839,\nstates\nthat\nall\nplants\nand\nanimals\nare\nmade\nup\nof\ncells.\n\u25cf\nIn\n1855,\nRudolf\nVirchow\nadvanced\nthe\ncell\nhypothesis\nby\nclaiming\nthat\nall\ncells\noriginate\nfrom\npre-existing\ncells.\n\u25cf\nThe\ndiscovery\nof\nthe\nmicroscopic\nuniverse\nwas\nmade\npossible\nby\nthe\ninvention\nof\nmagnifying\nlenses.",
  "\u25cf\nThe\ndiscovery\nof\nthe\nmicroscopic\nuniverse\nwas\nmade\npossible\nby\nthe\ninvention\nof\nmagnifying\nlenses.\nUnicellular\ncreatures\nhave\na\nsingle\ncell\nthat",
  "The Fundamental Unit Of Life.txt\nthat\nall\ncells\noriginate\nfrom\npre-existing\ncells.\n\u25cf\nThe\ndiscovery\nof\nthe\nmicroscopic\nuniverse\nwas\nmade\npossible\nby\nthe\ninvention\nof\nmagnifying\nlenses.\nUnicellular\ncreatures\nhave\na\nsingle\ncell\nthat\nperforms\nall\ntasks\nsuch\nas\nnourishment,\nrespiration,\nexcretion,\nand\nreproduction.\nAmoeba,\nChlamydomonas,\nParamecium,\nand\nBacteria,\nfor\nexample,\nhave\nsolitary\ncells\nthat\nmake\nup\nthe\nentire\norganism.\n\u25cf\nMulticellular\norganisms\nare\norganisms\nwith\na\nlarge\nnumber\nof\ncells\nthat\nperform\nmany\nroles.\nMulticellular\norganisms\nmight\nexhibit\nthemselves\nas\na\nsingle\ncell\nor\nas\na\ngroup\nof\ncells.",
  "Multicellular\norganisms\nmight\nexhibit\nthemselves\nas\na\nsingle\ncell\nor\nas\na\ngroup\nof\ncells.\nClass\nIX\nScience\nwww .vedantu.com\n1\n\u25cf\nFungi,\nplants,\nand\nmammals,\nfor\nexample,\nhave\nmany\ncells\nthat\nform\ntissues.\nA\nsingle\ncell\ngave\nrise\nto\nevery\nmulticellular\norganism.\n\u25cf\nAs\na\nresult,\nall\ncells\nare\nderived\nfrom\npre-existing\ncells.\nCells\nof\nvarious\ntypes\ncan\nalso\nbe\nfound\nin\nsome\ncreatures.\nCell\nTypes\nClass\nIX\nScience\nwww .vedantu.com\n2\n\u25cf\nThe\nshape\nand\nsize\nof\na\ncell\nare\ndetermined\nby\nthe\nfunction\nit\nperforms.\nSome",
  "The Fundamental Unit Of Life.txt\ncells.\nCells\nof\nvarious\ntypes\ncan\nalso\nbe\nfound\nin\nsome\ncreatures.\nCell\nTypes\nClass\nIX\nScience\nwww .vedantu.com\n2\n\u25cf\nThe\nshape\nand\nsize\nof\na\ncell\nare\ndetermined\nby\nthe\nfunction\nit\nperforms.\nSome\ncells\nalter\ntheir\nappearance.\nAmoeba,\nfor\nexample.\nIn\nother\nsituations,\nthe\ncell\nshape\nmay\nbe\nmore\nor\nless\nfixed\nand\nunique\nto\na\nspecific\ncell\ntype.\nEg:\nnerve\ncells.\n\u25cf\nEvery\nlive\ncell\nhas\nthe\nability\nto\ncarry\nout\ncertain\nbasic\noperations\nthat\nare\ncommon\nto\nall\nliving\nthings.\nIn\nmulticellular\norganisms\nlike\nhumans,\nthere\nis\na\ndivision\nof\nlabour.\nThis\nmeans\nthat\nvarious\nregions\nof\nthe\nhuman\nbody\nserve\ndiverse\npurposes.",
  "In\nmulticellular\norganisms\nlike\nhumans,\nthere\nis\na\ndivision\nof\nlabour.\nThis\nmeans\nthat\nvarious\nregions\nof\nthe\nhuman\nbody\nserve\ndiverse\npurposes.\n\u25cf\nWithin\na\nsingle\ncell,\nthe\ndivision\nof\nwork\nis\nalso\nvisible.\nIn\nreality,\neach\nof\nthese\ncells\nhas\nunique\ncomponents\nknown\nas\ncell\norganelles.\nEach\ntype\nof\ncell\norganelle\nhas\na\ndistinct\npurpose.\nThese\norganelles\nallow\na\ncell\nto\nlive\nand\naccomplish\nall\nof\nits\nactivities.\nThe\nbasic\nunit\nof\nthe\ncell\nis\nmade\nup\nof\nthese\norganelles.\nWhat\nare\nthe\nComponents\nof\na\nCell?\nWhat\nis\na\nCell's",
  "The Fundamental Unit Of Life.txt\npurpose.\nThese\norganelles\nallow\na\ncell\nto\nlive\nand\naccomplish\nall\nof\nits\nactivities.\nThe\nbasic\nunit\nof\nthe\ncell\nis\nmade\nup\nof\nthese\norganelles.\nWhat\nare\nthe\nComponents\nof\na\nCell?\nWhat\nis\na\nCell's\nStructural\nOrganisation?\nEvery\ncell\nhas\nthree\ndistinct\nfeatures:\na\nplasma\nmembrane,\na\nnucleus,\nand\na\ncytoplasm.\nDue\nto\nthese\ncharacteristics,\nall\nactivity\nwithin\nthe\ncell\nand\nexchanges\nbetween\nthe\ncell\nand\nits\nenvironment\nare\nfeasible.\nComponents\nof\na\nCell\nClass\nIX\nScience\nwww .vedantu.com\n3\nPlant\nCell\n\u25cf\nThe\nplasma\nmembrane,\nalso\nknown\nas\nthe\ncell\nmembrane,\nis\nthe\ncell's\noutermost\nlayer,\nwhich\nseparates\nthe\ncell's\ncontents\nfrom\nits\nsurroundings.",
  "It\nis\nmade\nup\nof\norganic\nmolecules\ncalled\nlipids\nand\nproteins\nand\nis\nflexible.\nThe\ncell\nmembrane's\nflexibility\nalso\nallows\nthe\ncell\nto\ntake\nin\nfood\nand\nother\nmaterials\nfrom\nits\nsurroundings.\nEndocytosis\nis\nthe\nterm\nfor\nsuch\na\nprocess.\nAmoeba,\nfor\nexample.\n\u25cf\nIt\nallows\nsome\nsubstances\nto\npass\ninto\nand\nout\nof\nthe\ncell.\nIt\nalso\ninhibits\nsome\nother",
  "The Fundamental Unit Of Life.txt\nand\nother\nmaterials\nfrom\nits\nsurroundings.\nEndocytosis\nis\nthe\nterm\nfor\nsuch\na\nprocess.\nAmoeba,\nfor\nexample.\n\u25cf\nIt\nallows\nsome\nsubstances\nto\npass\ninto\nand\nout\nof\nthe\ncell.\nIt\nalso\ninhibits\nsome\nother\nmaterials\nfrom\nmoving.\nAs\na\nresult,\nit's\nknown\nas\na\nselectively\npermeable\nmembrane.\n\u25cf\nDiffusion,\nosmosis,\nand\nother\nprocesses\ncan\nmove\nchemicals\nthrough\nthis\nsemi-permeable\nbarrier.\n\u25cf\nThe\ndifference\nbetween\ndiffusion\nand\nosmosis\nis\nas\nbelow:\nClass\nIX\nScience\nwww .vedantu.com\n4\nOSMOSIS\nDIFFUSION\nIt\nentails\nthe\ntransfer\nof\nsolvent\nmolecules.\nIt\nentails\nsolute\nmolecule\nmobility.",
  "It\nentails\nsolute\nmolecule\nmobility.\nMolecules\ntravel\nfrom\na\nlower\nsolute\nconcentration\nto\na\ngreater\nsolute\nconcentration.\nMolecules\ntravel\nfrom\na\ngreater\nsolute\nconcentration\nto\na\nlower\nsolute\nconcentration.\nIt\nonly\nhappens\nwhen\na\nsemi-permeable\nmembrane\nis\ncrossed.\nIt\ndoes\nnot\nnecessitate\nthe\nuse\nof\na\nsemi-permeable\nmembrane.\nExample:\nWhen\na\npotato\nslice\nis\nkept\nin\na\nhigh\nsucrose\nsolution,\nit\nshrinks.\nWhen\na\ndrop\nof\nink\nis\ndropped\ninto\na\nglass\nof\nwater,",
  "The Fundamental Unit Of Life.txt\nIt\ndoes\nnot\nnecessitate\nthe\nuse\nof\na\nsemi-permeable\nmembrane.\nExample:\nWhen\na\npotato\nslice\nis\nkept\nin\na\nhigh\nsucrose\nsolution,\nit\nshrinks.\nWhen\na\ndrop\nof\nink\nis\ndropped\ninto\na\nglass\nof\nwater,\nit\nspreads.\n\u25cf\nIf\nwe\nplace\nan\nanimal\nor\nplant\ncell\nin\na\nhypotonic\nsolution,\nit\nwould\nmost\ncertainly\nswell.\nIf\nthe\ncell\nis\nkept\nin\nan\nisotonic\nsolution,\nit\nwill\nmaintain\nits\nsize.\nThe\ncell\nwill\nshrink\nif\nthe\nsolution\nis\nhypertonic.\n\u25cf\nOsmosis\nis\na\nprocess\nthrough\nwhich\nunicellular\nfreshwater\norganisms\nand\nmost\nplants\nobtain\nwater.\n\u25cf\nCell\nwall:\nThe\ncell\nwall\nis\nonly\nfound\nin\nplant\ncells.",
  "\u25cf\nOsmosis\nis\na\nprocess\nthrough\nwhich\nunicellular\nfreshwater\norganisms\nand\nmost\nplants\nobtain\nwater.\n\u25cf\nCell\nwall:\nThe\ncell\nwall\nis\nonly\nfound\nin\nplant\ncells.\nCell\nwalls\nare\nmade\nof\ncellulose\nand\nare\nporous.\nIt\nkeeps\nthe\ncontents\nof\nthe\ncell\ndistinct\nfrom\nthe\nrest\nof\nthe\nworld.\nIt\ngives\nthe\ncell\nits\nform\nand\nprotects\nit.\n\u25cf\nPlants,\nfungi,\nand\nbacteria\nhave\ncell\nwalls\nthat\nallow\nthem\nto\nsurvive\nvery\ndilute\nexternal\nmedia\nwithout\nbursting.\n\u25cf\nPlasmolysis\nis\nthe\nprocess\nby\nwhich\ncells\nin\na\nhypertonic\nsolution\nlose\nwater.\n\u25cf\nNucleus:\nThe\nnucleus\nis\nprotected\nby\na\ndouble-layered",
  "The Fundamental Unit Of Life.txt\nthem\nto\nsurvive\nvery\ndilute\nexternal\nmedia\nwithout\nbursting.\n\u25cf\nPlasmolysis\nis\nthe\nprocess\nby\nwhich\ncells\nin\na\nhypertonic\nsolution\nlose\nwater.\n\u25cf\nNucleus:\nThe\nnucleus\nis\nprotected\nby\na\ndouble-layered\nmembrane\nknown\nas\nthe\nnuclear\nmembrane.\nThe\nnuclear\nmembrane\nhas\npores\nthat\nallow\nmaterial\nto\npass\nfrom\nthe\ninside\nto\nthe\noutside.\nChromosomes,\nwhich\nare\nmade\nup\nof\nDeoxyribonucleic\nClass\nIX\nScience\nwww .vedantu.com\n5\nacid\n(DNA)\nand\nproteins,\nare\nfound\nin\nthe\nnucleus.\nThe\nnucleus\nis\nin\ncharge\nof\nthe\ncell's\nentire\nactivity.",
  "The\nnucleus\nis\nin\ncharge\nof\nthe\ncell's\nentire\nactivity.\nNucleus\nand\nChromosome\n\u25cf\nThe\nnucleus\nis\nimportant\nin\ncell\ndivision\nand\ndevelopment\nbecause\nit\ncontains\ngenetic\ninformation\nin\nthe\nform\nof\nDNA.\nGenes\nare\nthe\nfunctional\nportions\nof\nDNA.\nProtein\nsynthesis\nand\ncharacter\ntransmission\nfrom\none\ngeneration\nto\nthe\nnext\nare\ncrucial\nfunctions\nof\nthe\nnucleus.\nIt\nis\nimportant\nfor\ncellular\nreproduction.\nIn\nsome\norganisms,\nthe\nnuclear\nmembrane\nis\nmissing,\nleaving\nonly\nnucleic\nacids\n(nucleoids)\nin\nthe\nnuclear\narea.\nProkaryotes\nare\nsuch",
  "The Fundamental Unit Of Life.txt\nof\nthe\nnucleus.\nIt\nis\nimportant\nfor\ncellular\nreproduction.\nIn\nsome\norganisms,\nthe\nnuclear\nmembrane\nis\nmissing,\nleaving\nonly\nnucleic\nacids\n(nucleoids)\nin\nthe\nnuclear\narea.\nProkaryotes\nare\nsuch\ncreatures.\nBacteria,\nfor\nexample.\nEukaryotes\nare\norganisms\nthat\nhave\na\nnuclear\nmembrane\nin\ntheir\ncells.",
  "Prokaryotes\nare\nsuch\ncreatures.\nBacteria,\nfor\nexample.\nEukaryotes\nare\norganisms\nthat\nhave\na\nnuclear\nmembrane\nin\ntheir\ncells.\nClass\nIX\nScience\nwww .vedantu.com\n6\nProkaryotic\nCells\nEukaryotic\nCells\nVery\nminute\nin\nsize\nFairly\nlarge\nin\nsize\nThe\nnuclear\nregion\n(nucleoid)\nis\nnot\nsurrounded\nby\na\nnuclear\nmembrane\nNuclear\nmaterial\nsurrounded\nby\na\nNuclear\nmembrane\nSingle\nchromosomes\npresent\nMore\nthan\none\nchromosome\npresent\nNucleolus\nabsent\nNucleolus\npresent\nMembrane-bound\ncell\norganelles\nare\nabsent\nMembrane-bound\ncell\norganelles\nare\npresent\nCell\ndivision\nby\nfission\nor\nbudding\n(no\nmitosis)\nCell\ndivision\nby\nmitosis\nor\nmeiosis\nProkaryotic\nand\nEukaryotic\nChromosome\nClass\nIX\nScience\nwww .vedantu.com\n7\n\u25cf\nCytoplasm:\nThe\nfluid\ncontent\ninside\nthe\nplasma\nmembrane\nis\nreferred\nto\nas\ncytoplasm.",
  "It's\na\nvicious\njelly-like\nsubstance\nthat",
  "The Fundamental Unit Of Life.txt\nand\nEukaryotic\nChromosome\nClass\nIX\nScience\nwww .vedantu.com\n7\n\u25cf\nCytoplasm:\nThe\nfluid\ncontent\ninside\nthe\nplasma\nmembrane\nis\nreferred\nto\nas\ncytoplasm.\nIt's\na\nvicious\njelly-like\nsubstance\nthat\ncovers\nthe\nentire\ncell\nsave\nthe\nnucleus.\nIt\nalso\ncontains\na\nvariety\nof\nspecialised\ncell\norganelles,\neach\nof\nwhich\nserves\na\nspecific\npurpose\nfor\nthe\ncell.\n\u25cf\nThe\nendoplasmic\nreticulum,\nRibosomes,\nGolgi\napparatus,\nMitochondria,\nPlastids,\nLysosomes,\nand\nVacuoles\nare\nexamples\nof\ncell\norganelles.\nThey're\nvital\nsince\nthey\nperform\nsome\nof\nthe\nmost\nimportant\njobs\nin\ncells.",
  "They're\nvital\nsince\nthey\nperform\nsome\nof\nthe\nmost\nimportant\njobs\nin\ncells.\n\u25cf\nEndoplasmic\nreticulum\n(ER):\nThe\nER,\nor\nendoplasmic\nreticulum,\nis\na\nvast\nnetwork\nof\nmembrane-bound\ntubes\nand\nsheets.\nIt\nacts\nas\na\nconduit\nfor\nthe\nmovement\nof\nmaterials,\nparticularly\nproteins,\nbetween\ndistinct\ncytoplasmic\norgans\nor\nbetween\nthe\ncytoplasm\nand\nthe\nnucleus.\nIt\nalso\nserves\nas\na\ncytoplasmic\nscaffolding\nthat\nprovides\na\nsurface\nfor\ncertain\nof\nthe\ncell's\nmetabolic\noperations.\nRough\nendoplasmic\nreticulum\nand\nsmooth\nendoplasmic",
  "The Fundamental Unit Of Life.txt\nthe\ncytoplasm\nand\nthe\nnucleus.\nIt\nalso\nserves\nas\na\ncytoplasmic\nscaffolding\nthat\nprovides\na\nsurface\nfor\ncertain\nof\nthe\ncell's\nmetabolic\noperations.\nRough\nendoplasmic\nreticulum\nand\nsmooth\nendoplasmic\nreticulum\nare\nthe\ntwo\nforms\nof\nER.\nEndoplasmic\nReticulum\nClass\nIX\nScience\nwww .vedantu.com\n8\na.\nRER:\nThese\nare\nrough\non\nthe\noutside\nand\nare\nlinked\nto\nribosomes.\nProtein\nsynthesis\nis\ncarried\nout\nby\nthese\ncells.\nb.\nSER:\nThese\nare\nsmooth\non\nthe\noutside\nand\nhave\nnothing\nto\ndo\nwith\nribosomes.\nIt\naids\nin\nthe\nproduction\nof\nfat\nmolecules,\nalso\nknown\nas\nlipids.",
  "b.\nSER:\nThese\nare\nsmooth\non\nthe\noutside\nand\nhave\nnothing\nto\ndo\nwith\nribosomes.\nIt\naids\nin\nthe\nproduction\nof\nfat\nmolecules,\nalso\nknown\nas\nlipids.\nIt\nalso\naids\nin\nthe\ndetoxification\nof\na\nvariety\nof\ntoxins\nand\nmedications.\n\u25cf\nMembrane\nbiogenesis:\nEF\nproduces\nproteins\nand\nlipids\nthat\naid\nin\nthe\nformation\nof\nthe\ncell\nmembrane.\nMembrane\nbiogenesis\nis\nthe\nname\ngiven\nto\nthis\nprocess.\n\u25cf\nThe\nGolgi\nApparatus\nis\nnamed\nafter\nCamillo\nGolgi,\na\nscientist\nwho\nwas\nthe\nfirst\nto\ndescribe\nit.\nA\nstack\nof\nmembrane-bound\ncisternae\nmakes\nup\nthe\nGolgi.\nGolgi\nApparatus\nClass\nIX\nScience\nwww .vedantu.com\n9\n\u25cf\nThese",
  "The Fundamental Unit Of Life.txt\nis\nnamed\nafter\nCamillo\nGolgi,\na\nscientist\nwho\nwas\nthe\nfirst\nto\ndescribe\nit.\nA\nstack\nof\nmembrane-bound\ncisternae\nmakes\nup\nthe\nGolgi.\nGolgi\nApparatus\nClass\nIX\nScience\nwww .vedantu.com\n9\n\u25cf\nThese\nmembranes\nare\nfrequently\nconnected\nto\nthe\nmembranes\nof\nthe\nER,\nand\nso\nform\npart\nof\na\ncomplex\ncellular\nmembrane\nsystem.\nIts\nresponsibilities\ninclude\nstoring,\nmodifying,\nand\npacking\nitems\nin\nvesicles.\nIt\nhas\na\nrole\nin\nthe\ndevelopment\nof\nlysosomes\nas\nwell.\n\u25cf\nLysosomes:\nLysosomes\nare\nenzyme-filled\nmembranous\nsacs.\nRER\nproduces\nthese\nenzymes.\nThey\nare\na\ntype\nof\ncell\nwaste\ndisposal\ndevice.",
  "\u25cf\nLysosomes:\nLysosomes\nare\nenzyme-filled\nmembranous\nsacs.\nRER\nproduces\nthese\nenzymes.\nThey\nare\na\ntype\nof\ncell\nwaste\ndisposal\ndevice.\nThey\naid\nin\nthe\ncleaning\nof\nthe\ncell\nby\ndigesting\nforeign\nsubstances\nas\nwell\nas\nworn-out\ncell\norganelles.\nHydrolytic\nenzymes\nin\nlysosomes\nare\ncapable\nof\ndigesting\ncellular\nmacromolecules.\nWhen\na\ncell\nis\ndamaged,\nthe\nlysosome\nmay\nburst,\nallowing\nthe\ncell's\nenzymes\nto\ndigest\nit.\nAs\na\nresult,\nlysosomes\nare\nreferred\nto\nas\n\u2018suicidal\nbags'.\nLysosomes\\\nClass\nIX\nScience\nwww .vedantu.com\n10\n\u25cf\nMitochondria\nare\ncellular",
  "The Fundamental Unit Of Life.txt\nlysosome\nmay\nburst,\nallowing\nthe\ncell's\nenzymes\nto\ndigest\nit.\nAs\na\nresult,\nlysosomes\nare\nreferred\nto\nas\n\u2018suicidal\nbags'.\nLysosomes\\\nClass\nIX\nScience\nwww .vedantu.com\n10\n\u25cf\nMitochondria\nare\ncellular\norganelles\nthat\nare\nknown\nas\nthe\n\"powerhouses\nof\nthe\ncells.\"\nA\ndouble\nmembrane\nseparates\nthese\nfrom\nthe\nrest\nof\nthe\nbody.\nThe\nexterior\nmembrane\nis\nsmooth,\nand\nthe\ninner\nmembrane\nis\nfolded\ninto\ncristae\nfolds.\nThe\ncristae\nexpands\nthe\ncellular\nrespiration\narea.\nMitochondria\nproduce\nATP\nmolecules,\nwhich\nare\nused\nto\nrelease\nenergy.\nATP\nis\nreferred\nto\nas\nthe\ncell's\n\"energy\ncurrency.\"",
  "Mitochondria\nproduce\nATP\nmolecules,\nwhich\nare\nused\nto\nrelease\nenergy.\nATP\nis\nreferred\nto\nas\nthe\ncell's\n\"energy\ncurrency.\"\nMitochondria\nhave\ntheir\nown\nDNA\nDNA\nribosomes\nand\nare\ncapable\nof\nproducing\nsome\nproteins.\nMitochondria\n\u25cf\nPlastids\nare\na\ntype\nof\nbacterium\nfound\nsolely\nin\nplant\ncells.\nThere\nare\ntwo\nvarieties\nof\nthese:\nchromoplasts\n(coloured\nplastids)\nand\nleucoplasts\n(white\nplastids)\n(white\nor\ncolourless\nplastids).\nChloroplasts\nare\nplastids\nthat\ncontain\nthe\npigment\nchlorophyll.\nThese\nare\nnecessary\nfor\nplant\nphotosynthesis.\nChromoplasts",
  "The Fundamental Unit Of Life.txt\nplastids)\nand\nleucoplasts\n(white\nplastids)\n(white\nor\ncolourless\nplastids).\nChloroplasts\nare\nplastids\nthat\ncontain\nthe\npigment\nchlorophyll.\nThese\nare\nnecessary\nfor\nplant\nphotosynthesis.\nChromoplasts\nare\norganelles\nthat\ncontribute\nvibrant\ncolours\nto\nplant\nstructures\nsuch\nas\nbuds,\nflowers,\nand\nleaves.\nClass\nIX\nScience\nwww .vedantu.com\n11\nOrganelles\nthat\nstore\nstarch,\noils,\nand\nprotein\ngranules\nare\nknown\nas\nleucoplasts.\nPlastids\nare\nmade\nup\nof\nseveral\nmembrane\nlayers\nthat\nare\nencased\nin\nthe\nstroma.\nPlastids\nhave\nDNA\nand\nribosomes\nof\ntheir\nown.\nVacuoles:\nPlant\nand\nanimal\ncells\nboth\nhave\nvacuoles,\nwhich\nare\nmembrane-bound\ncompartments.",
  "Plastids\nhave\nDNA\nand\nribosomes\nof\ntheir\nown.\nVacuoles:\nPlant\nand\nanimal\ncells\nboth\nhave\nvacuoles,\nwhich\nare\nmembrane-bound\ncompartments.\nThese\nare\nsolid\nor\nliquid-filled\nstorage\nsacs.\nIn\nanimal\ncells,\nthey\nare\nsmall,\nwhereas\nin\nplant\ncells,\nthey\nare\nlarger.\nPlant\ncells\nhave\nsap-filled\nvacuoles\nthat\ngive\nthe\ncell\nturgidity\nand\nstiffness.\nWater,\nwaste\nmaterials,\nand\ncompounds\nincluding\namino\nacids,\ncarbohydrates,\nand\nproteins\nare\nall\nstored\nin\nthese\norganelles.\nSpecialised\nvacuoles\nserve\na\nvital",
  "The Fundamental Unit Of Life.txt\ngive\nthe\ncell\nturgidity\nand\nstiffness.\nWater,\nwaste\nmaterials,\nand\ncompounds\nincluding\namino\nacids,\ncarbohydrates,\nand\nproteins\nare\nall\nstored\nin\nthese\norganelles.\nSpecialised\nvacuoles\nserve\na\nvital\nfunction\nin\nthe\nexpulsion\nof\nexcess\nwater\nand\ncertain\nwastes\nfrom\nthe\ncell\nin\nsome\nunicellular\norganisms.\nDifference\nBetween\nPlant\nCells\nand\nAnimal\nCells:\nThe\ndifference\nbetween\nplant\nand\nanimal\ncells\nis\nenlisted\nbelow:\nPLANT\nCELLS\nANIMAL\nCELLS\nClass\nIX\nScience\nwww .vedantu.com\n12\nPlant\ncells\npossess\na\ncell\nwall.\nAnimal\ncells\ndo\nnot\npossess\na\ncell\nwall.\nChloroplasts\nare\npresent\nin\nplant\ncells.\nAnimal\ncells\ndo\nnot\npossess\nchloroplasts.\nPlant\ncells\npossess\nlarge\nvacuoles.",
  "Animal\ncells\ndo\nnot\npossess\na\ncell\nwall.\nChloroplasts\nare\npresent\nin\nplant\ncells.\nAnimal\ncells\ndo\nnot\npossess\nchloroplasts.\nPlant\ncells\npossess\nlarge\nvacuoles.\nAnimal\ncells\nhave\nmany\nsmall\nvacuoles.\nHigher\nplants\ndo\nnot\npossess\ncentrioles.\nAnimal\ncells\ndo\ncontain\ncentrioles.\nCell\nDivision\nCell\ndivision\nis\nthe\nprocess\nby\nwhich\nnew\ncells\nare\nformed\nin\norganisms\nfor\ngrowth,\nreplacing\nold,\ndead,\nand\ninjured\ncells,\nand\nfor\nreproduction.\nThere\nare\ntwo\nmain\ntypes\nof\ncell\ndivision:",
  "The Fundamental Unit Of Life.txt\nDivision\nCell\ndivision\nis\nthe\nprocess\nby\nwhich\nnew\ncells\nare\nformed\nin\norganisms\nfor\ngrowth,\nreplacing\nold,\ndead,\nand\ninjured\ncells,\nand\nfor\nreproduction.\nThere\nare\ntwo\nmain\ntypes\nof\ncell\ndivision:\nmitosis\nand\nmeiosis.\n\u25cf\nMitosis\nis\nthe\ntype\nof\ncell\ndivision\nresponsible\nfor\ngrowth\nand\ntissue\nrepair.\nIn\nmitosis,\na\nmother\ncell\ndivides\ninto\ntwo\nidentical\ndaughter\ncells,\neach\nhaving\nthe\nsame\nnumber\nof\nchromosomes\nas\nthe\nmother\ncell.\n\u25cf\nMeiosis\noccurs\nin\nthe\nreproductive\norgans\nto\nform\ngametes,\nwhich\nare\nnecessary\nfor\nsexual\nreproduction.\nMeiosis\nresults\nin\nfour\nnew\ncells,\neach\nwith\nhalf\nthe\nnumber\nof\nchromosomes\ncompared\nto\nthe\nmother\ncell.",
  "Meiosis\nresults\nin\nfour\nnew\ncells,\neach\nwith\nhalf\nthe\nnumber\nof\nchromosomes\ncompared\nto\nthe\nmother\ncell.\nThis\nreduction\nis\nimportant\nto\nmaintain\nthe\nchromosome\nnumber\nin\noffspring\nafter\nfertilisation.\nThe\nreduction\nin\nchromosome\nnumber\nduring\nmeiosis\nensures\nthat\nwhen\ngametes\ncombine,\nthe\noffspring\nhave\nthe\ncorrect\nnumber\nof\nchromosomes.\nClass\nIX\nScience\nwww .vedantu.com\n13",
  "Is Matter Around Us Pure.txt\nClass  IX Science   1  \n \n \nRevision Notes  \nClass  - 9 Science  \nChapter 2 - Is Matter Around Us Pure  \n \nIntroduction:  \n\u25cf Substances are one or more components that make up matter.  \n\u25cf A substance is a sort of matter that cannot be divided into any other types \nof matter by physical means, according to science.  \n\u25cf The term \"pure substance\" refers to a substance that has only one \ncomp onent and nothing else.  \n\u25cf Substances are frequently mixed with one another, and the result is referred \nto as a mixture.  \n \n              \n \nClass  IX Science   2",
  "Is Matter Around Us Pure.txt\nPure and impure substances:  \nA. A pure material  is one that has only one type of particle. Water, sulphur, \nhydrogen, carbon, and other pure substances (made up of only one type of \nparticle) are known as pure substances since they can't be separated by any \nphysical process. A pure substance has a consta nt composition, as well as \na constant melting and boiling point.  \nB. Impure Substances : Impure substances are those that are made up of two \nor more types of particles (atoms or molecules) that may be separated \nusing physical methods. All of the substances in t he mixtures are impure. \nSalt solution, sugar solution, milk, seawater, air, sugarcane juice, soft \nbeverages, sharbat, rocks, minerals, petroleum, LPG, biogas, tap water, \ntea, coffee, paint, wood, soil and bricks,  are some examples of mixes. It is \npossible for a mixture to be homogeneous or heterogeneous. A mixture's \ncomposition, as well as its melting and boiling points, are not fixed.",
  "Is Matter Around Us Pure.txt\nTypes of Pure Substances:  \n\u25cf Pure substances are divided into two categories. These are elements and \ncompounds, respectively.  \n\u25cf A pure substance's simplest or basic form, which cannot be broken down \ninto anything simpler than it by physical or chemical techniques, is called \nan element.  \n\u25cf Dalton's later research revealed that atoms are the simplest form of matter. \nIt can now be defined as a pure substance made up of only one type of \natom. Hydrogen, carbon, oxygen, and other elements are examples.  \n\u25cf Solids, liquids, and gases are all examples  of elements. At room \ntemperature, sodium and carbon elements, for example, are solids, mercury \nand bromine elements are liquids, and hydrogen and oxygen elements are \ngases. In reality, solids make up the vast majority of the elements. Elements \nare further  divided into three types:  \na. Metals  \nb. Non-metals  \nc. Metalloids",
  "Is Matter Around Us Pure.txt\nMetals:  \nA metal is a malleable and ductile element that conducts electricity. Metals \ninclude Iron, Copper, Aluminium, Zinc, Silver, Gold, Platinum, Chromium, \nSodium, Potassium, and Magnesium, to name a few.  \n \nNon-Metals:  \nNon-metals, as their name implies, are diametrically opposed to metals, implying \nthat their properties are vastly different. They are relatively few in number, but Class  IX Science   3  \n \n \nthey are vital to the survival of living organisms. Non -metals make up just \napproximately fo urteen to fifteen percent of the elements in the periodic table. \nCarbon, Sulphur, Phosphorous, Hydrogen, and Oxygen are only a few examples.  \n \nComparison among the Properties of Metals and Non -Metals:  \n                     Metals                    Non-Metals  \nMetals are durable and powerful. \nThey have an extremely high \ntensile strength.  \n \nMetals have a resonant quality to \nthem. When struck, they generate a \nringing sound.",
  "Is Matter Around Us Pure.txt\nMetals have a resonant quality to \nthem. When struck, they generate a \nringing sound.  \n \nMetals can be polished and are \nlustrous (bright).  \n \nAt normal temperature, metals are \nsolids (e xcept mercury which is a \nliquid metal).  \n \nMetals are excellent heat and \nelectrical conductors.  \n \nMetals are ductile and malleable. \nMetals can be hammered into thin \nsheets and pulled into fine wires in \nthis way.  Non-metals aren't very durable. \nTheir tensile strength is modest.  \n \nNon-metals do not have a resonant \nquality.  \n \nNon-metals have a dull appearance  \nand cannot be polished (except \niodine which is a lustrous non -\nmetals).  \n \nAt room temperature, non -metals \nmight be solids, liquids, or gases.  \n \nNon-metals are poor heat and \nelectrical conductors (except \ndiamond which is a good conductor \nof heat, and graphite w hich is a \ngood conductor of electricity).  \n \nNon-metallic materials are brittle.",
  "Non-metals are poor heat and \nelectrical conductors (except \ndiamond which is a good conductor \nof heat, and graphite w hich is a \ngood conductor of electricity).  \n \nNon-metallic materials are brittle. \nThey aren't malleable or ductile in \nthe least.",
  "Is Matter Around Us Pure.txt\nNon-metallic materials are brittle. \nThey aren't malleable or ductile in \nthe least.  \n \n \nMetalloids:  \nThere are a few elements that have properties that are similar to both metals and \nnon-metals. Metalloids are elements that exist on the edge of existence. Boron \n(B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Bismuth (Bi), \nTellurium (Te), a nd Polonium are some examples of metalloids (Po).  \n Class  IX Science   4",
  "Is Matter Around Us Pure.txt\nIllustration \u2013 1: \nGive two reasons why you believe copper is a metal and sulphur is not.  \nAns: The following are the two qualities that indicate that copper is a metal and \nsulphur is a non -metal:  \nCopper  \na. Copper is ductile and malleable. It can be pulled into wires and \npounded into thin sheets.  \nb. Copper is a good heat and electrical conductor.  \nSulphur  \na. Sulphur is neither ductile nor malleable. It's fragile. When \nhammered or strained, sulphur fractures into fragments.  \nb. Sulphur is a poor heat and electrical conductor.  \n \nTypes of Mixture:  \n\u25cf Compounds:  \nIt's also a pure substance, similar to the elements. It does, however, indicate a \nchemically integrated mixture of two or more elements.  \n\u201cA pure substance containing two or more elements mixed in a predetermined \nmass proportion\u201d  \nExample: \n2HO (water), \n2CO (Carbon dioxide), \n3NH (Ammonia) etc.",
  "Is Matter Around Us Pure.txt\n\u25cf Compound Types:  The compounds have been divided into two groups. These \nare the following:  \n(a) Inorganic compounds:  These compounds are usually made up of non -\nliving materials like rocks and minerals. Common salt, marble, washing \nsoda, baking soda, carbon dioxide, ammonia, sulphuric acid, and other \ninorganic compounds are examples.  \n(b) Organic compounds:  The term \"organ\" r efers to several organs found in \nliving organisms. As a result, organic chemicals are compounds derived \nfrom living organisms, such as plants and animals. It has been discovered \nthat carbon is a fundamental component of all organic molecules. As a \nresult, organic substances are frequently referred to as \" carbon \ncompounds .\"",
  "Is Matter Around Us Pure.txt\n\u25cf Compound Characteristics:  The following are key compound \ncharacteristics:  \na. A pure compound is made up of the same constituents.  \nb. The properties of a pure compound are completely different from the \nproperties of the element from which it is created.  Class  IX Science   5",
  "Is Matter Around Us Pure.txt\nc. Because a compound is generated by a chemical process, it has qualities \nthat are distinct from the elements from which it is formed. Hyd rogen gas, \nfor example, is combustible, but oxygen is a supporter of combustion. The \nchemical reaction between the two gases results in the formation of water. \nIt isn't combustible and doesn't enable burning.  \nd. It puts an end to or extinguishes combustion. W e frequently use water to \nput out fires.  \ne. Chemical compounds' constituents cannot be separated mechanically. \nCompound formation necessitates energy exchange.  \nf. Because of the following factors, water is termed a compound: Physical \nmethods cannot separate water into its constituent\u2019s hydrogen and oxygen.  \ng. Water's properties are vastly different from those of its constituents, \nhydrogen and oxygen. Hydrogen is flamma ble, but oxygen promotes \ncombustion. Water differs from the other two in that it extinguishes fire.",
  "Is Matter Around Us Pure.txt\nhydrogen and oxygen. Hydrogen is flamma ble, but oxygen promotes \ncombustion. Water differs from the other two in that it extinguishes fire.  \nh. When hydrogen and oxygen are burned to make water, heat and light are \nreleased. The chemical make -up of water is constant.  \ni. The components hydrogen and oxyge n are present in a \n1:8  mass ratio.  \nj. Under atmospheric pressure of 1 atmosphere, water has a stable boiling  \npoint of \n1 0 0 \u00b0 C  (or \n3 7 3  K ) (or \n7 6 0  m m ).",
  "Is Matter Around Us Pure.txt\nMixture:  \n\u25cf \u201cA mixture is a combination of two or more substances (elements of \ncompounds) that are not chemically combined but may also be present in \nany proportion.\u201d There are two different kinds of mixtures:  \na. Homogeneous mixture  \nb. Heterogeneous mixture  \n\u25cf Compounds and el ements are pure substances. In scientific terminology, \nmixtures are not pure substances.  \n \nHomogeneous mixture:  \n\u25cf \u201cWhen diverse ingredients or substances in a combination exist in one \nsingle phase with no obvious borders of separation, it is said to be \nhomogenous. The composition of a homogenous mixture is consistent \nthroughout.\u201d Here are a few instances of homogenous  mixtures:  \n\u25cf Because the dissolved salt is evenly distributed all through the salt water \nsample, it is a homogenous combination. All solutions are termed \nhomogeneous since the dissolved component is present throughout the \nsolution in the same quantity.  Class  IX Science   6",
  "Is Matter Around Us Pure.txt\n\u25cf Air is also a mixture of gases such as nitrogen, oxygen, carbon dioxide, \nwater vapours, inert gases, and others. All of the gases in the air combine \nto form a single phase, the gaseous phase. Air can also be considered a \nsolution.  \n\u25cf The term \"solution\" refers to  any homogenous mixture.  \n \nHeterogeneous Mixtures:  \n\u25cf \u201cIf a combination does not have a homogeneous composition and visible \nborders of separation between parts, it is said to be heterogeneous.\u201d  \n\u25cf Here are some instances of heterogeneous mixtures:  \n\u25cf A heterogeneous mixture is one that consists of sand and common s alt. \nThese are undoubtedly present in the same phase, namely the solid phase, \nyet they have distinct separation boundaries. The sand and ordinary salt \nparticles are plainly visible in the combination.  \n\u25cf Oil and water, too, produce a heterogeneous mixture. Bo th constituents are \nliquids, but their separation boundaries are different.  \n\u25cf Oil and water can be found in different layers.",
  "Is Matter Around Us Pure.txt\nDistinction between compounds and a mixture:  \n               Compounds                     Mixtures  \nA compound is made up of two or \nmore components that have been \nchemically joined.  \n \nThe elements of a compound are \npresent in a set mass ratio. This \nproportion will not change.  \n \nCompounds are always \nhomogeneous , meaning that their \nmakeup is the same throughout.  \n \nThe elements of a compound lose \ntheir identities, i.e., the constituting \nelemen t's features are not visible in \nthe compound.  Two or more elements or \ncompounds ar e merely blended in \nthe mixture rather than chemically \ncombined.  \n \nThe ingredients of a mixture are \npresent in a predetermined ratio. It \ncan vary.  \n \nIn nature, mixtures can be either \nhomogeneous or heterogeneous.  \n \nThe constituents of a mixture lose \ntheir identities, i.e., a mixture \ndisplays all of the constituents' \nqualities. In the development of a Class  IX Science   7",
  "Is Matter Around Us Pure.txt\nThe constituents of a mixture lose \ntheir identities, i.e., a mixture \ndisplays all of the constituents' \nqualities. In the development of a Class  IX Science   7  \n \n \nEnergy in the form of heat, light, or \nelectricity is either absorbed or \nevolved during the synthesis of a \ncompound.  \n \nPhysical separation of parts in a \ncompound is impossible.  mixture, no energy change is \nobserved.  \n \nPhysical means can easily separate \nthe parts of a combination.  \n \nIllustration \u2013 2: \nI. Explain why air is a mixture rather than a compound.  \nAns: Because of the following factors, air is considered a mixture:",
  "Is Matter Around Us Pure.txt\nIllustration \u2013 2: \nI. Explain why air is a mixture rather than a compound.  \nAns: Because of the following factors, air is considered a mixture:  \n \na. By using a physical process or fractional distillation, air can be divided \ninto its constituents such as oxygen, nitrogen, and other gases (or liquid \nair). \nb. The properties of all the gases present in air can be seen. For example, \noxygen and air both enable burning; carbon dioxide turns lime -water \nmilky, and air turns lime -water milky as well, though at a far slower rate.  \nc. When air is generated by mixing the proper proportions of oxygen, \nnitrogen, carbon dioxide, argon, water vapour, and other gases, heat and \nlight are neither given out nor absorbed.  \nd. Because different parts of the world have varied concentrations of \nvarious gases, air has a variable makeup. There isn't a set formula for it.  \ne. There is no fixed boiling point for liquid air.",
  "Is Matter Around Us Pure.txt\nII. Sort the following items into element, compound, and mixture categories: \nSodium, Soil, Sugar Solution, Silver, Calcium Carbonate, Tin Silicon, Coal, \nAir, Soap, Methane, Carbon Dioxide, Blood  \nAns: The following is how we can categorise the provided materials into           \nelements, compounds, and mixtures:  \na. Sodium, Silver, Tin, and Silicon are some of the elements . \nb. Calcium carbonate, soap, methane, and carbon dioxide are examples of \ncompounds . \nc. Soil, Sugar Solution, Coal, Air, and Blood are examples of mixtures . \n \nIII. List the elements included in the following compounds and their names:  Class  IX Science   8",
  "Is Matter Around Us Pure.txt\nIII. List the elements included in the following compounds and their names:  Class  IX Science   8  \n \n \nQuicklime (a), hydrogen bromide (b), baking soda (c), and potassium \nsulphate (d)  \nAns:  Calcium oxide (CaO) is quicklime. Calcium (Ca) and oxygen (\n2O ) are two \nof the elements found in it (O).  \na. HBr stands for hydrogen bromide. Hydrogen (H) and Bromine (Br) are \nthe elements present (Br).  \nb. Sodium hydrogen carbonate , or , is the chemical formula for \nbaking soda. It contains the elements sodium (Na), hydrogen (H), carbon \n(C), and oxygen (O).  \nc. \n24K SO  is the chemical formula for potassium sulphate. It contains the \nelements potassium (K), sulphur (S), and oxygen (O).",
  "Is Matter Around Us Pure.txt\nSolutions, Suspensions and Colloids:  \n\u25cf The instance of Solution Solute: A solute is a substance that is dissolved to \nform a solution, such as salt or sugar.  \n\u25cf A solute's solubility is defined as its ability to dissolve in water. \u201cA solute's \nsolubility is defined as the greatest amount of solute t hat may be dissolved \nin 100 gm of solvent to form a saturated solution at a particular \ntemperature.\u201d  \n\u25cf It is directly proportional to temperature.  \nmass of soluteSolubility = 100mass of solvent\uf0b4\n \n\u25cf On the basis of the solubility of the solute, solutions can be further split \ninto tw o categories  - Saturated and Unsaturated Solutions . \n\u25cf A solution is considered to be saturated  if it contains the maximum \namount of the solute dissolved in it at a given temperature and no more \nsolute can be dissolved.  \n\u25cf At a given temperature, a solution is said to be unsaturated if more solute \ncan be dissolved in it.",
  "Is Matter Around Us Pure.txt\nSuspensions:  \n\u25cf Are made up of compounds that are insoluble in water. \u201cA heterogeneous \nmixture is one in which minute solid particles are dispersed throughout a \nliquid without dissolving in it.\u201d Examples include chalk water, muddy \nwater, milk of magnesia, and fluorine water.  \n\u25cf Suspension Characteristics  \nClass  IX Science   9",
  "Is Matter Around Us Pure.txt\na. A heterogeneous suspension is made up of two phases. One phase is made \nup of solid particles, while the other is made up of the liquid in which they \nare suspended or spread.  \nb. A suspension's particle size is greater than 100 microns (or \n710\u2212 m). \nc. A suspension's particles can be observed with the naked eye as well as \nunder a microscope.  \nd. Ordinary filter sheets may easily separate the solid particles present in the \nsuspension. For this reason, no specific filter sheets are required.  \ne. Suspensio n particles are inherently unstable. When the suspension is not \ndisrupted, they settle down after a while. This is referred to as precipitate.  \nf. It's worth noting that the terms suspension and precipitate are \ninterchangeable. Suspension is represented by the  solid particles in their \nsuspended state. When they settle, they form a precipitate.",
  "Is Matter Around Us Pure.txt\nColloids:  \n\u25cf A colloid is a type of solution in which the size of the solute partials lies \nsomewhere between real solutions and suspension. Colloidal solutions, \nlike suspensions, are heterogeneous in nature, but the particles are smaller \nand more evenly dispersed. It i s in the range of 1 nm to 100 nm, i.e., \nbetween real solution and suspension particle sizes. Because the particle \nsizes are so similar to what we see in solutions, most colloidal solutions \nappear to be homogeneous, just like genuine solutions. However, thi s is \nnot the case.  \n\u25cf In everyday life, we come across a wide range of colloidal solutions. \nTypical examples include smoke from factory chimneys, tooth paste, ink, \nblood, soap solutions, jellies, and starch solution in water.  \n\u25cf Colloidal solutions are heterogen eous mixtures, as we already established. \nThis signifies that the constituents aren't all present at the same time. In a \ncolloidal solution, there are actually two phases. Dispersed phase and",
  "Is Matter Around Us Pure.txt\nThis signifies that the constituents aren't all present at the same time. In a \ncolloidal solution, there are actually two phases. Dispersed phase and \ndispersion medium are the terms for these.",
  "Is Matter Around Us Pure.txt\nCharacteristic of Co lloidal Solutions : \n\u25cf Colloidal solutions appear to be homogeneous but are actually \nheterogeneous in nature.  \nThis is due to the particle size (1 nm to 100 nm) in a colloidal \nsolution, which is relatively near to the particle size in suspension. \nHowever, under a microscope, these can be seen.  \n \n\u25cf Colloidal solutions are a two phase system  Class  IX Science   10  \n \n \nWe've already established th at colloidal solutions are a two -phase \nsystem. Dispersed phase and dispersion medium are these terms. \nBecause of this, colloidal solutions are diverse in character.  \n \n\u25cf Colloidal particles pass through ordinary filter papers  \nColloidal solutions flow through r egular filter sheets like real \nsolutions in the vast majority of circumstances. This is due to the \ndispersed phase's or colloidal particles' tiny size. To remove these \nparticles from the dispersion media, special filter sheets called as \nultra-filter papers  must be utilised.",
  "Is Matter Around Us Pure.txt\n\u25cf Colloidal particles carry charge  \nThe dispersed phase particles in a colloidal solution remain scattered \nor suspended, as we have learned. They do not approach close to one \nother as they would if they were suspended. The presence of a ch arge \n(positive or negative) on these particles causes this. Please keep in \nmind that all of the particles in a colloidal solution have the same \ncharge.  \nAs a result, these particles with identical charges repel one other and \nremain dispersed or suspended. H emoglobin, starch, gelatin, and \nmetals such as copper, silver, gold, and metal sulphides, for \nexample, contain negative charge on their particles.  \nMetal hydroxides, such as iron, aluminium, calcium, and others, \nhave a positive charge on their particles.  \n \n\u25cf Particles in a colloidal solution follow zigzag path",
  "Is Matter Around Us Pure.txt\n\u25cf Particles in a colloidal solution follow zigzag path  \n \nBecause of their small size, colloidal particles are generally invisible. Their \nroute, though, can be observed under a microscope. These particles travel \nin a zigzag pattern. This motion can be observed while viewing a movie in \na theatre. Dust particles ar e present in the beam of light that falls on the \nscreen from behind. They walk in a zigzag pattern.  \nClass  IX Science   11  \n \n \nIn 1828, Robert Brown, an English physicist, was the first to detect such \ncolloidal particle movement. Brownian motion  is the name for this type \nof motion.",
  "Is Matter Around Us Pure.txt\nIn 1828, Robert Brown, an English physicist, was the first to detect such \ncolloidal particle movement. Brownian motion  is the name for this type \nof motion.  \n \nTyndall effect: Scattering of light by colloidal particles : \n\u25cf The particles in a colloidal solution are large enough to scatter light. This \ncan be demonstrated as follows. When a light beam is focused on a \ncolloidal solution (for example, soap solution) in a dark environment, the \npath of the light beam is lighted and visible when viewed from the side. \nBecause colloidal particles are large enough to scatter light falling on them \nin all directions, the path of the light beam becomes visible. We can \nperceive th e course of the light beam because of the scattered light that \nenters our eyes.",
  "Is Matter Around Us Pure.txt\nProperty   Suspension   Colloidal \nsolution   True \nsolution  \nParticle size   > 100 nm   1 to 100 nm   < 1 nm  \nSeparation  by \nordinary   filtration  Possible   Not possible   Not possible  \nSettling of particles   Settle of \ntheir own Settle only \non centrifugation  Do not settle  \nAppearance   Opaque   Generally    \ntransparent  Transparent  \nTyndall effect   Shows   Shows   Does not \nshow  \nDiffusion of particles   Do not diffuse   Diffuse slowly   Diffuse \nrapidly  \nClass  IX Science   12  \n \n \nBrownian movement   May show   Show   May or may \nnot  shown  \nNature \nheterogeneous   Heterogeneous   Homogeneous",
  "Is Matter Around Us Pure.txt\nBrownian movement   May show   Show   May or may \nnot  shown  \nNature \nheterogeneous   Heterogeneous   Homogeneous   \n \n\u25cf To tell the difference between a colloid and a solution. The tyndall effect \ncan be used to distinguish between colloids (or colloidal solutions) and real \nsolutions. A soap solution, for example, scatters a ray of light travelling \nthrough it, making its pat h visible; thus, soap solution is a colloid (or colloidal \nsolution). A beam of light travelling through salt solution, on the other hand, \nis not scattered.  \n \nClassification of Colloids : \nColloids are classified according to the physical state of dispersed phase \n(solute) and the dispersion medium (solvent). These are  \n(i) Sol.  \n(ii) Solid sol.  \n(iii) Aerosol  \n(iv) Emulsion  \n(v) Foam  \n(vi) Solid foam  \n(vii) Gel",
  "Is Matter Around Us Pure.txt\nTechnical \nname   of \ncolloid  Dispersed    \nphase  Dispersion    \nmedium  Examples  \nsol.  Solid   Liquid   Ink, soap solution, \nstarch  solution, most paints  \nsolid sol.   Solid   Solid   Coloured gemstone (kike \nruby glass)  \naerosol   (i) solid   \n(ii) liquid  Gas  \nGas Smoke, automobile \nexhausts  hairspray, fog, \nmist, clouds  \nemulsion   Liquid   Liquid   Milk, butter, face cream   Class  IX Science   13  \n \n \nfoam   Gas  Liquid   Fire-extinguisher foam, \nsoap bubbles, shaving \ncream, beer  foam  \nsolid  foam  Gas  Solid   Insulating foam, foam \nrubber,  sponge  \ngel  Solid   Liquid   Jellies, gelatin",
  "Is Matter Around Us Pure.txt\nIllustration \u2013 3: \n(i) A solution contains 30 g of sugar dissolved in 370 g of water. \nCalculate the concentration of this solution.  \nAns: We know that concentration of solution \nMass of solute100Mass of solution=\uf0b4  \nHere, mass of solute (sugar) = 30 g and the mass of solvent (water) = 370 \ng \nSo, Mass of solution \n=  Mass of solute \n+  Mass of solvent \n 3 0   3 7 0  \u00a0 4 0 0= + =\ng  \nNow, putting the values of \u2018mass of solute\u2019 and \u2018mass of solution\u2019 in the \nabove formula, we get:  \nConcentration of solution \n30 30100 7.5%400 4= \uf0b4 = =  \n \n(ii) If 110 g of salt is present in 550 g of solution, calculate the \nconcentration of solution.",
  "Ans: Here, Mass of solute (salt) \n 1 1 0=  g and, Mass of solution \n 5 5 0=  g  \nNow, we know that; concentration of solution  \nMass of solute100Mass of solution=\uf0b4  \n110100 20%550= \uf0b4 =",
  "Is Matter Around Us Pure.txt\n(iii) If 2 mL of acetone is present in 45 mL of its aqueous solution \ncalculate the concentration of this solution.   \nAns: Here, volume of solute (acetone) \n 2=  mL and, volume of solution \n 45=\n mL  \nNow, we know that: concentration of solution  \nMass of solute100Mass of solution=\uf0b4  \n2100 4.4%45= \uf0b4 =\n Class  IX Science   14  \n \n \n(iv) 12 grams of potassium sulphate dissolves in 75 grams of water 60\u00b0C.  \nWhat is its solubility in water at that temperature?   \nAns: Here we have been given that 75 grams of water dissolves 12 grams \nof potassium sulphate. We have to find how much potassium sulphate will \ndissolve in 100 grams of water. Now, 75 g of water dissolves \n 12=  g of \npotassium sulphate  \nSo, 100 g of water will dissolve \n12100 1675= \uf0b4 =  g of potassium sulphate.",
  "Now, 75 g of water dissolves \n 12=  g of \npotassium sulphate  \nSo, 100 g of water will dissolve \n12100 1675= \uf0b4 =  g of potassium sulphate. \nThus, the solubility of potassium sulphate in water is 16 g at \n60\u00b0C .",
  "Is Matter Around Us Pure.txt\nSeparation of mixture:  \n\u25cf To tell the difference between a colloid and a solution. The tyndall effect \ncan be used to distinguish between colloids (or colloidal solutions) and real \nsolutions. A soap solution, for example, scatters a ray of light travelling \nthrough it, making its pat h visible; thus, soap solution is a colloid (or \ncolloidal solution). A beam of light travelling through salt solution, on the \nother hand, is not scattered.  \n \nCommonly used process which are used to separate the constituents of \nmixture are : \na. Sublimation  \nb. Filtration  \nc. Centrifugation  \nd. Evaporation  \ne. Crystallization  \nf. Chromatography  \ng. Distillation  \nh. Fractional Distillation  \ni. Separating funnel  \n\u25cf We'll look at the following three scenarios to discover how to separate \nmixtures:  \n1. A combination of two solids  \n2. A solid and a liquid mixture  \n3. A combination of two liquids.",
  "Is Matter Around Us Pure.txt\n\u25cf Separation of a two -solid combination:  \nThe following procedure is used to separate a mixture of two substances.  \na. Using a suitable solvent (a mixture of sugar and sand)  \nb. Using the sublimation process (ammonium chloride and common salt)  \nc. Using a magnet (mixture of iron filling and sulphur power)  Class  IX Science   15",
  "Is Matter Around Us Pure.txt\n\u25cf Separation of mixture of solid and a liquid  \na. By filtration  \nb. By centrifugation  \nc. By evaporation  \nd. By crystallization   \ne. By chromatography  \nf. By distillation  \ng. To Separate Cream From Milk  \nh. Centrifugation:  It is a method for separating suspended particles of a \nsubstance from a liquid in which the mixture (or sperm) is rotate d at a \nhigh speed in a centrifuge, forcing denser particles to the bottom and \nlighter particles to the top layer.  \ni. By the process of chromatography:  \nWater serves as the solvent in our ink, and the dye is soluble in it. The \ndye particles are carried away by the rising water on the filter paper. A \ndye is usually a blend of two or more colours. The colour component \nthat is more soluble in water rises faster, and the colours segregate as a \nresult.  \nChromatography is the technique of separating the components of a  \nmixture. The Greek word kroma means \"colour.\" Chromatography is a",
  "Is Matter Around Us Pure.txt\nresult.  \nChromatography is the technique of separating the components of a  \nmixture. The Greek word kroma means \"colour.\" Chromatography is a \ntechnique for separating those solutes that dissolve in the same solvent. \nIt was first used to separate colours, hence the name.",
  "Is Matter Around Us Pure.txt\nj. Separation of dyes in black ink using chromatography:  \nThe two methods are used to separate a combination of two liquids: \nmiscible liquid (which mixes together in all proportions and forms a \nClass  IX Science   16  \n \n \nsingle layer) and immiscible liquid (which does not mix with each other \nand forms distinct layers).  \n \nk. By the fractional d istillation (for miscible liquid):  \nFractional distillation is used to separate a combination of two or more \nmiscible liquids with a difference in boiling points of less than 25 K, \nsuch as for the separation of different gases from air, distinct factions \nfrom petroleum product, and so on.  \nThe apparatus is similar to that used for simple distillation, except that \nbetween the distillation flask and the condenser is a fractionating \ncolumn.  \nA simple fractionating column is a glass bead -filled tube. The beads \nserve as a surface for the vapour to c ool and condense on multiple \noccasions.",
  "Is Matter Around Us Pure.txt\nl. Separation of the Gases of the Air  \nNitrogen, oxygen, argon, carbon dioxide, helium, neon, krypton, and \nxenon, among other gases, make up air. Fractional distillation of liquid \nair separates the various gases of air from one another. This distinction \nis made due to the fact that the boiling points of the various gases in the \natmosphere differ (when in liquid form).",
  "Is Matter Around Us Pure.txt\nIllustration \u2013 4: A mixture of sand, water, and mustard oil is administered \nto you. What method will you use to separate the various components of \nthis mixture?  \nAns: There are three ingredients in this mixture: sand, water, and mustard \noil. Sand is now a solid that is insoluble in both water and mustard oil. \nMustard oil and water are incompatible liq uids.  \n(a) The sand, water, and mustard oil combination is filtered. As a residue, \nsand is left on the filter paper. The filtrate is made up of water and \nmustard oil.  \n(b) A separating funnel is used to collect the filtrate, which contains both \nwater and mustard oil. In a  separating funnel, the lower layer is water, \nand the upper layer is mustard oil. The bottom layer of water is \nremoved first by opening the separating funnel's stop -cock. Mustard \noil stays in the separating funnel and can be extracted individually.",
  "work and energy.txt\n   1  \n \n  \nRevision Notes for Class 9 Science  \nChapter 10 \u2013 Work and Energy \n \nIntroduction:  \nFor the average person, the term \"work\" refers to any task that requires bodily or mental effort. \nHowever, in physics, the phrase has a different meaning. It denotes a measurable quantity. We \nsay that a force has done work on an object when it acts on it a nd causes it to move in the \ndirection of the force.  \nWhen you push a book on a table, you apply force to the book, which causes it to move in the \ndirection of the force. We say the force has done its job.  \nYou will be exhausted if you push a wall, but the wall will not move. There is no work done \nin terms of science.  \n \n1. Work and Measurement of Work  \nWhen a force acts on an object and the point of application moves in the direction of the force, \nwork is said to be completed.",
  "work and energy.txt\n1. Work and Measurement of Work  \nWhen a force acts on an object and the point of application moves in the direction of the force, \nwork is said to be completed.  \n \n2. Conditions to be Satisfied for Work to be Done:  \n\u2022 There must be some force acting on the object   \n\u2022 The point of application of force must move in the force's direction  \n\u2022 Work is calculated by multiplying the force by the distance travelled.  \nW=F  S\uf0b4\n  \n \n \n    2  \n \n  \nWhere W denotes the amount of work done, F is the force exerted, and S denotes the distance \ntravelled by the moving object. The amount of work completed is a scalar quantity.  \n \n3. Work Done When the Force is not Along the Direction of Motion:  \nAssume that a constant force F acts on a body, resulting in a displacement S as illustrated in \nthe diagram. Let \n\uf071  be the angle formed by the force and displacement directions.  \n \n \nDisplacement in the direction of the force = Component of \nS  along AX \nAC=  \nBut we know that,  \ncos\uf071=",
  "work and energy.txt\nDisplacement in the direction of the force = Component of \nS  along AX \nAC=  \nBut we know that,  \ncos\uf071=\n \nadjacent side hypotenuse  \ncosAC\nS\uf071=\n \ncos AC S \uf071=\n \n \n \n \n    3  \n \n  \nDisplacement in the direction of the force \ncosS\uf071=  \nWork done =Force \n\uf0b4  displacement in the direction of force  \ncos W FS \uf071=\n \nIf the displacement S is in the direction of the force \n0,cos 1 FS \uf071==  \nThen,   \n1 W FS=\uf0b4\n  \nW FS=\n  \nIf,  \n90\uf071\uf0b0=\n \ncos90 0\uf0b0=\n \nTherefore, \n. 0 0 W F S= \uf0b4 =  i.e., no work is done by the force on the body.  \n \n \n4. The Centripetal Force is Activated When a Stone at the End of a String is Whirled \nAround in a Circle at a Constant Speed.   \nThis force is perpendicular to the stone's velocity at any given time.",
  "4. The Centripetal Force is Activated When a Stone at the End of a String is Whirled \nAround in a Circle at a Constant Speed.   \nThis force is perpendicular to the stone's velocity at any given time. So, despite the fact that it \nis responsible for retaining the stone in a circular motion, this force does  not work.   \n \n \n    4  \n \n  \n \n \n5. SI Unit of Work:  \nW F S=\uf0b4",
  "work and energy.txt\n   4  \n \n  \n \n \n5. SI Unit of Work:  \nW F S=\uf0b4\n \nSI unit of \nF  is \nN  and that of \nS  is \nm  [N = newton]   \nSI unit of work\nNm=\uf0b4  \n1Nm  is defined as \n1  joule.  \ni.e., \n1  joule \n1Nm=  \nSo, SI unit of work is Joule . \nA joule is the amount of work done when the point of application of a one -newton force moves \none metre in the direction of the force.  \n \n \n \n    5  \n \n  \nThe joule unit of measurement is named after British scientist James Prescott Joule.  \nJoule is represented by the letter 'J.'  \nKilojoule and megajoule are higher units of work.  \n1\nkilojoule\n1000J=  \n1\n kilojoule\n310J=  or, \n1\nmegajoule\n1000,000 J =  \n1\nmegajoule\n610J=  \n \n6.",
  "1\nkilojoule\n1000J=  \n1\n kilojoule\n310J=  or, \n1\nmegajoule\n1000,000 J =  \n1\nmegajoule\n610J=  \n \n6. Energy:  \nAnything that has the ability to work has energy. The capacity to work is defined as energy. \nThe amount of work that a body can accomplish is how much energy it has. As a result, the SI \nunit of energy is the joule.",
  "work and energy.txt\n7. Different Forms of Energy:  \nMechanical energy, thermal energy, electrical energy, and chemical energy are examples of \ndiverse types of energy. We'll look at mechanical energy in this chapter. Mechanical energy is \ndivided into two types: kinetic energy and potential energy.  \n \n8. Kinetic Energy:  \nA fast -moving stone can break a windowpane, falling water can crank turbines, and moving \nair can rotate windmills and drive sailboats, as we all know. The moving body in all of these  \n \n \n    6  \n \n  \nsituations has energy. The body in motion does the work. Kinetic energy is the form of energy \nthat is possessed by moving objects.  \n\u201cKinetic energy is defined as the energy that an object possesses as a result of its motion. The \nletter 'T' is used to symbolise kinetic energy. Kinetic energy is present in all moving objects.\u201d",
  "work and energy.txt\n9. Expression for Kinetic Energy of a Moving Body:  \nConsider a mass 'm' body that is initially at rest. Allow the body to begin moving with a \nvelocity of 'v' and cover a distance of 'S' when a force ' F' is applied to it. In the body, the force \ncauses acceleration 'a'. \nWhen the force 'F' moves the body over a distance 'S' it does work, and this work is stored in \nthe body as kinetic energy.  \nW F S=\uf0b4\n \u2026\u2026..(1)  \nF ma=\n    [Newton\u2019s second law of motion]  \nW mas=\n \u2026\u2026\u2026.(2)  \nAlso, \n222 v u aS\u2212= [Newton\u2019s third law of motion]  \n202v aS\u2212=\n[Initial velocity \n0u=  as the body is initially at rest]  \n22v aS=\n \n2\n2vaaS\uf0de=\n \nSubstituting the value of 'a' in equation \n()2  we get,   \n2\n2mvWSS=\n  \n \n \n    7",
  "work and energy.txt\n2\n2vaaS\uf0de=\n \nSubstituting the value of 'a' in equation \n()2  we get,   \n2\n2mvWSS=\n  \n \n \n    7  \n \n  \n2\n2mvW=\n \u2026\u2026..(3)  \nBut since work done is stored in the body as its kinetic energy equation (3) can be written as  \nKinetic energy \n()T\n2 1\n2mv=  \nWe can deduce from the above equation that a body's kinetic energy is proportional to \n()1  its \nmass and \n()2  the square of its velocity.  \n \n10. Momentum and Kinetic Energy:  \nAll moving objects, we know, have momentum. The product of a body's mass and velocity is \ndefined as its momentum.  \nLet's look at how a body's kinetic energy is related to its momentum.  \nConsider a body of mass 'm' moving with a velocity 'v'.",
  "The product of a body's mass and velocity is \ndefined as its momentum.  \nLet's look at how a body's kinetic energy is related to its momentum.  \nConsider a body of mass 'm' moving with a velocity 'v'. Then, the momentum  of the body is \ngot by \np mv=  \nBut, Kinetic energy \n()T\n2 1\n2mv=  \nSubstituting the value of 'v' in equation \n()1  we get,  \n2\n2\n2\n21\n2\n1\n2\n2pTmm\npmm\np\nm\uf0e6\uf0f6=\uf0e7\uf0f7\uf0e8\uf0f8\n=\n=\n  \n \n \n    8",
  "work and energy.txt\n   8  \n \n  \n11. Potential Energy:  \nConsider the following scenarios:   \n\u2022 Water held in a reservoir can be used to rotate turbines at a lower level. Because of its \nlocation, water kept in a reservoir has energy.  \n\u2022 A hammer strike on a nail fixes it, however, if the hammer is simply placed on the nail, \nit barely moves. The raised hammer possesses energy as a result of its posture.  \n\u2022 A winding key -driven toy car: The spring is wound when we turn the key. When we let \ngo, the toy car's wheels begin to roll as the spring unwinds, and the car moves if left on \nthe floor. The wound spring is energised. The gain in energy is attributed to the  spring's \nlocation or condition.  \n\u2022 A Toy Car Driven by a Winding Key:  \n \n \n \n\u2022 Stretched String Gains Potential Energy  \n \n \n \n    9  \n \n  \n \n \n \n\u2022 The energy possessed by an object as a result of its position or state is known as \npotential energy.",
  "work and energy.txt\n\u2022 Stretched String Gains Potential Energy  \n \n \n \n    9  \n \n  \n \n \n \n\u2022 The energy possessed by an object as a result of its position or state is known as \npotential energy.  \n \n12. Expression for Potential Energy:  \nConsider a mass 'm' object lifted to a height 'h' above the surface of the earth. The work done \nagainst gravity is stored as potential energy in the object (gravitational potential energy).  \nAs a result, potential energy equals the work done in lifting an object to a certain height.  \n \n \n \n    10  \n \n  \n \n \nObject of Mass 'm', Raised Through a Height 'h' \nPotential energy\nFS=\uf0b4 \u2026\n()1  \nBut \nF mg=  [Newton's second law of motion]  \nSh=\n \nSubstituting for \nF and \nS  in equation \n()1 , we get  \nPotential energy =\nmg h\uf0b4  \nPotential energy\nmgh=  \nIt is obvious from the above relationship that an object's potential energy is proportional to its \nheight above the ground.  \n \n \n \n \n \n    11",
  "work and energy.txt\n13. Law of Conservation of Energy:  \nLet's have a look at what's going on in the following scenarios:  \n\u2022 Steam engine: Coal is burned in a steam engine. Water is converted to steam by the heat \ngenerated by coal burning. The locomotive is moved by the expansion force of steam \non the piston of the engine. Chemical energy is transferred to heat energy, which is then \nconverted to steam's expansion power. When the locomotive travels, this energy is \nconverted to kinetic energy.  \n\u2022 Hydroelectric power plant: Water from a reservoir is forced to fall on turbines that are \nheld at a lower level and connected to the coils of an a.c. generator. The potential energy \nof the water in the reservoir is converted to kinetic energy, and the kinet ic energy of \nfalling water is converted to turbine kinetic energy, which is then converted to electrical \nenergy. As a result, if the energy in one form vanishes, an equal quantity of energy in",
  "work and energy.txt\nfalling water is converted to turbine kinetic energy, which is then converted to electrical \nenergy. As a result, if the energy in one form vanishes, an equal quantity of energy in \nanother form emerges, resulting in constant total energy.",
  "work and energy.txt\n14. Law of Conservation of Energy:  \n\u201cThe law of conservation of energy asserts that energy cannot be generated or destroyed, only \nconverted from one form to another.\u201d  \nLet us now demonstrate that the preceding law applies to a freely falling body. Allow a body \nof mass 'm' to begin falling down from a height 'h' above the earth. In this example, we must \ndemonstrate that the body's total energy (potential energy + kinetic energy) remains unchanged \nat points A, B,  and C,i.e., potential energy is totally turned into kinetic energy.   \n \n \n    12  \n \n  \n \n \nBody of Mass 'm'placed at a height 'h' \nAt \nA , \nPotential energy \nmgh=  \nKinetic energy \n2 1\n2mv=  \n102m=\uf0b4\n \nKinetic energy \n0= [ the velocity is zero as the object is initially at rest]  \nTotal energy at \nA =Potential energy + Kinetic energy  \n0 mgh=+\n \nTotal energy at \nA\nmgh= \u2026\n()1  \n \n \n \n    13",
  "work and energy.txt\nTotal energy at \nA\nmgh= \u2026\n()1  \n \n \n \n    13  \n \n  \nAt B, \nPotential energy \nmgh=  \n() mg h x=\u2212\n [height from the ground is \n()hx\u2212  \nPotential energy \nmgh mgx=\u2212  \nThe body covers the distance x with a velocity 'v'. We make use of the third equation of motion \nto obtain the velocity  of the body.",
  "We make use of the third equation of motion \nto obtain the velocity  of the body.  \n222 v u aS\u2212=\n \nHere,   \n0u=\n \nag=\n and  \nSx=\n \n202v gx\u2212=\n \n22v gx=\n \nKinetic energy \nmgx=  \nTotal energy at \nB=  Potential energy + Kinetic energy  \nmgh mgx mgx= \u2212 +\n \nmgh=\n\u2026\n()2  \nAt C, \nPotential energy \n() 00 m g h= \uf0b4 \uf0b4 =   \n \n \n    14  \n \n  \nPotential energy\n0=  \nKinetic energy\n2 1\n2mv=  \nThe distance covered by the body is \nh , \n222 v u aS\u2212=\n \nHere, \n0,u=  \nag=\n and  \nSh=\n \n202v gh\u2212=\n \n22v gh\uf0de=\n  \nKinetic energy \n122m gh=\uf0b4  \nKinetic energy \nmgh=  \nTotal energy \nmgh=  \nTotal energy at \nC = Potential energy + Kinetic Energy  \n0mgh=+",
  "work and energy.txt\nHere, \n0,u=  \nag=\n and  \nSh=\n \n202v gh\u2212=\n \n22v gh\uf0de=\n  \nKinetic energy \n122m gh=\uf0b4  \nKinetic energy \nmgh=  \nTotal energy \nmgh=  \nTotal energy at \nC = Potential energy + Kinetic Energy  \n0mgh=+\n \nTotal energy at \nC mgh=  \u2026 \n()3  \nThe total energy of the body is constant at all points, as shown by equations 1, 2 and 3. As a \nresult, we can deduce that the law of conservation of energy applies to a freely falling body.  \n  \n \n \n    15",
  "work and energy.txt\n   15  \n \n  \n15. Power:  \nImagine two pupils positioned at opposite ends of a 100 -meter track transferring 10 bricks \nfrom one end to the other. What is the total amount of work that each of them has completed? \nThe amount of work done is consistent, but the time it takes to complete  it varies. We calculate \nthe work done in unit time to determine which of the two is the fastest.  \nThat is, the amount of work done and the amount of work done per unit of time are two separate \nquantities.  \nPower is defined as the amount of work done per unit of time or the rate at which work is \ncompleted.  \nThe letter 'P' stands for power.  \nwPt=\n, where \nw  is the work done and \nt  is the time taken  \nPower can be described as the amount of energy consumed in a given amount of time, as \nenergy represents the capacity to conduct work.  \nEPt=\n, where \nE  is the energy consumed.  \n \n16. SI unit of power:  \nwPt=",
  "work and energy.txt\n16. SI unit of power:  \nwPt=\n \nThe joule is the SI unit of work, and the second is the SI unit of time. As a result, the SI unit \nof power is the joule/second. 1 watt = 1 joule/second  \nWhen an agent performs one joule of work in one second, its power is measured in watts. \nKilowatts and megawatts are higher power units.   \n \n \n    16  \n \n  \n1\n kilowatt\n1000= watts  \n1\n kilowatt\n310=  watts  \nOr, \n1  megawatt = 1000,000 watts  \n1\n megawatt\n610= watts  \nAnother unit of power is horsepower.   \n1\n horse power\n746=  watts  \n \n17. Commercial Unit of Energy:  \nThe SI unit joule is insufficient for expressing very high amounts of energy. As a result, we \nuse a larger measure known as the kilowatt -hour (kWh) to express energy.  \nA kWh is the amount of energy utilised by an electrical device in one hour at \n1000 /Js\n()1kW\n.",
  "As a result, we \nuse a larger measure known as the kilowatt -hour (kWh) to express energy.  \nA kWh is the amount of energy utilised by an electrical device in one hour at \n1000 /Js\n()1kW\n. \nA kilowatt -hour is a unit of measurement for energy utilised in homes, businesses, and \nindustries.",
  "work and energy.txt\n18. Numerical Relation Between SI and Commercial Unit of Electrical Energy:  \nSI unit of energy is Joule. Commercial unit of energy is kWh . \n1 1 1kWh kW h=\uf0b4\n \n1 1000 3600kWh W s=\uf0b4\n \n1 3600000kWh J=\n  \n \n \n    17  \n \n  \n61 3.6 10kWh J=\uf0b4\n \n11kWh unit=",
  "Matter in Our Surroundings.txt\nClass  IX Science    1 \n \n \n \n \n \n \nRevisio n Notes  \nClass 9 Science  \nChapter 1 - Matter in Our Surrounding - Summary Note  \n \n\u2022 Introduction  \n\u27a2 Everything around us is formed of matter: a pencil, a pen, a table, the food  \nwe consume, the clothes we wear, the walls of our homes. But what is  \nmatter?  \n\u27a2 Anything that occupies space, has mass, and can be sensed by our senses  \nis considered matter. In other words, the term \"matter\" refers to all of the  \nsubstances and materials that make up the cosm os. \n \n\u2022 Composition of Matter  \n \n\u27a2 According to ancient Indian philosophers, matter is made up of five \nconstituents or tatvas, according to study found in our sacred books and \nscriptures.  \n \n \n \n \nClass  IX Science    2 \n \n \n \n \n \n \nIllustration\n1:\u2212  How many different ways did ancient Indian philosophers \nclassify matter?  \nA. \n2   \nB. \n6   \nC. \n7   \nD. \n5   \nAns: \n()D",
  "Matter in Our Surroundings.txt\nClass  IX Science    2 \n \n \n \n \n \n \nIllustration\n1:\u2212  How many different ways did ancient Indian philosophers \nclassify matter?  \nA. \n2   \nB. \n6   \nC. \n7   \nD. \n5   \nAns: \n()D   \n \n\u2022 Matter is made up of Particles   \n\u27a2 Now that we have defined matter let us ask ourselves the question \u2013 What  \nis matter made up of?  \n\u27a2 All matter comprises of very small particles.  \n\u27a2 All matter can be broken up in a similar manner to get very small particles.  \n\u27a2 Hence we now conclude that all matter is made up of small particles.  \n \n \nIllustration  \n2:\u2212 Which of the following are matter?  \nChair, air, love, smell, hate, almonds, thought, cold, cold -drink, smell of \nperfume.  \nAns: chair, air, almond, cool drink",
  "Matter in Our Surroundings.txt\nIllustration  \n2:\u2212 Which of the following are matter?  \nChair, air, love, smell, hate, almonds, thought, cold, cold -drink, smell of \nperfume.  \nAns: chair, air, almond, cool drink  \n \n\u2022 Properties of Matter   \nSmall particles of matter make up all matter. Some features are shared by all of \nthese particles. A theory c alled Kinetic Theory of Matter explains  forth these \nfeatures.  \nSimply said, The Kinetic Theory of Matter States is a theory that describes how \nmatter changes throughout time.  \nA. All matter is made up of tiny particles.  \nB. There is space between these particles.  \nC. The particles are in constant motion.  \nD. The particles are attracted to one another.  \n \n \n \nClass  IX Science    3",
  "Matter in Our Surroundings.txt\n\u2022 Particles of  Matter have space between them   \n\u27a2 Small particles make up matter, and these particles have small spaces  \nbetween them.  \n\u27a2 These areas are not visible to the naked eye, yet particles of o ther matter  \ncan pass through them without changing their volume.  \n  \n\u2022 Particles of Matter are continuously moving   \nParticles in matter are constantly moving. Three types of motion were seen in \nthe matter particles.  \nA. Translatory Motion  - It occurs when particles move in straight lines and  \nchange direction without losing energy after interacting with another  \nparticle or the container's wall. When compared to liquids, translational  \nmotion is greatest in gases and least in solids.  \nB. When particle s travel about their own axis, this is known as rotational  \nmotion . This motion is comparable to the earth's rotation around its  \naxis.In gases and liquids, rotational motion will be quite high.",
  "Matter in Our Surroundings.txt\nmotion . This motion is comparable to the earth's rotation around its  \naxis.In gases and liquids, rotational motion will be quite high.  \nC. Vibrational Motion  - When particles move back and forth around a  \ncentral point. Solids have the greatest amount of motion because the  \nparticles are held in a hard framework.",
  "Matter in Our Surroundings.txt\n\u2022 Particles of Matter attract each other   \n\u27a2 The force with which they attract one another differs depen ding on the  \nmatter.  \n\u27a2 The force is modest in some types of materials (waste paper, matchsticks)  \n(as we can tear or break them easily).  \n\u27a2 The force is large in other types of material (iron nail) (as we cannot break  \nthe nail easily).  \n \nIllustration\n3:\u2212  When sugar dissolves in water, what happens to it? What \nhappens to the sugar? What does the dissolution of sugar in water tell you about \nthe nature of matter?  \nAns:  \na) When sugar dissolves in water, the solid sugar crystals are broke n up into \nmicroscopic particles.  \nb) The sugar particles interact with the water particles in the gaps between \nthem (to form sugar solution).  \nc) Sugar dissolving in water indicates that the stuff (in this case, sugar and \nwater) is made up of minute particles.  There are voids between the particles of \nstuff (in this case, water).  \n Class  IX Science    4",
  "Matter in Our Surroundings.txt\n\u2022 Diffusion   \n\u27a2 \u201cThe mixing and spreading out of a substance with another substance due  \nto the movement or motion of its particles is called diffusion.\u201d  \n\u27a2 The process of one substance diffusing into another continues until a  \nhomogenous mixture is achieved. Let's have a loo k at an example.  \n\u27a2 Put a crystal of potassium permanganate (purple colour) in one of the  \n\u27a2 beakers that is full of water. Gradually, you'll notice that the purple  \ncolored crystal begins to diffuse or dissolve into water, and after a whil e,it \nturns purple.  \n \n \n\u2022 Diffusion in Gases   \nGases have a very fast diffusion rate. Because gas particles move very swiftly in \nall directions, this is the case.",
  "Matter in Our Surroundings.txt\n\u2022 Diffusion in Gases   \nGases have a very fast diffusion rate. Because gas particles move very swiftly in \nall directions, this is the case.  \n \nExamples \n\u20131:  \n\u27a2 Even from a long distance, the smell of food being prepared in the kitchen  \nreaches us.  \n\u27a2 The smell of hot, sizzling food reaches us even when we are a long way  \naway, but we must approach close to get the smell of cold food.  \n\u27a2 This is because the rate of diffusion of hot gases is substantially faster than  \nthe rate of diffusion of cold gases released by cold food.  \n \nExample \n\u20132:   \n\u27a2 When someone opens a bottle of perfume in one corner of a room, the  \nscent soon travels throughout the space.  \n\u27a2 When a perfume bottle is opened, the liquid perfume soon turns into \nvapour (or gas).  \n\u27a2 The scent vapours flow quickly in all directions in the air, mixing with the  \nair particles and spreading across the room.  \nClass  IX Science    5",
  "Matter in Our Surroundings.txt\nExample  \n\u27a2 The diffusion of a strong smelling chemical (ethyl mercaptan) found in  \nthe cooking gas into the air detects the leaking of cooking gas (LPG) in  \nour houses.  \n \n\u2022 Diffusion in Liquids   \nLiquid diffusion is slower than gas diffusion. This is due to the fact that particles \nin liquids move slower than particles in gases.  \n \n\u2022 Solid in  Liquid   \n\u27a2 When a crystal of potassium permanganate is placed in the bottom of a  \nbeaker of water, the purple colour of the potassium permanganate  \nprogressively spreads throughout the water.",
  "Matter in Our Surroundings.txt\n\u2022 Liquid in Liquid :  \n\u27a2 When a drop of ink is dropped into a beaker of water, the  colour of the ink  \nspreads across the entire water in the beaker; this is due to the diffusion o  \nink particles into water.  \n\u27a2 Gases like carbon dioxide and oxygen are necessary for aquatic plants and  \nanimals to survive. The carbon dioxide and oxygen gases in  the air (or  \natmosphere) diffuse into and dissolve in water (ponds, lakes, and rivers).  \nAquatic plants use dissolved carbon dioxide to prepare food through  \nphotosynthesis, whereas aquatic animals breathe using dissolved oxygen  \nin the water.  \n \n\u2022 Diffusion in Solids   \nSolid -state diffusion is an extremely slow process.",
  "Matter in Our Surroundings.txt\n\u2022 Diffusion in Solids   \nSolid -state diffusion is an extremely slow process.  \n \nExample :  \n\u27a2 If we write something on a blackboard and then leave it filthy for a long  \ntime (say, 10 to 15 days), cleaning the blackboard becomes quite tough.  \nThis is owing to the fact that certain chalk particles have dispersed into  \nthe backboard's surface.  \n\u27a2  When two metal blocks are closely linked together and left undisturbed  \nfor several years, the particles of one metal permeate into the other metal.  \nGases dissipate quickly. A gas's rate of diffusion is proportional to the  \nsquare root of its density.  \n \n \n Class  IX Science    6",
  "Matter in Our Surroundings.txt\nClass  IX Science    6 \n \n \n \n \n \n \n\u2022 Force of Attraction (or Cohesion)  \n\u27a2 Between the particles of matter, there is an attraction force that binds them  \ntogether. The force of attraction is the attraction between particles of the \nsame substance (or cohesion).  \n\u27a2 In general, the force of attraction is greatest in solid matter particles and  \nleast in gaseous matter particles.  \n \nIllustration  \n4:\u2212  Analyse  the effects of diffusion in different states of matter, \nsuch as solid, gas, and liquid.  \nAns:  \nSolid Liquid Gases\uf03c\uf03c   \n         Slow        Fast            Very Fast  \n \n\u2022 States of  Matter",
  "Matter in Our Surroundings.txt\n\u2022 States of  Matter  \n \n \n\u27a2 Solids  have a defined volume and shape. They are more difficult to break  \nthan liquids and gases.  \n\u27a2 Liquids  have a specific volume but not a specific shape. They take on the  \nshape of the container they're housed in.  \n\u27a2 Gases  do not have a defined shape or volume. They take up all of the  \navailable space and take on the shape of the container in which they are  \nkept.  \n\u27a2 Plasma  - At extremely high temperatures, the plasma state is a fused and  \nionic condition of matter (like the core of the sun, stars). Because it is  \nmade up of positive ions and a pool of electrons, the fused ionic mass is  \nneutral. Around 99 percent of the  universe is made up of fused ionic  \nmatter.  \n \n \nClass  IX Science    7",
  "Matter in Our Surroundings.txt\nS.no\n. Solid  Liquid  Gas \n1.  Solids have fixed shape \nand definite volume  Liquids have fixed \nvolume but no definite \nshape.  Gases have no \nfixed  \nvolume and shape  \n2.  Solids have high \ndensity  Liquids have high \ndensity but less than \nsolids.  Gases have low \ndensity.  \n3.  Solids show only slight \nexpansion on heating.  Liquids show slight \nexpansion on heating \nbut more than solids.  Gases expand \nconsiderably  \non heating . \n4.  They have slight or no \ncompressibility.  They have slight \ncompressibility but \nmore than solids.  They have high \ncompressibility.  \n5.  Solids do not flow.  Liquids generally flow \neasily.  Gases flow freely.  \n6.  They have their melting \nand boiling points \nabove room \ntemperature.  They have their melting \npoint below room \ntemperature.  They have their \nmelting and boiling \npoints both below \nroom temperature.  \n7.",
  "Gases flow freely.  \n6.  They have their melting \nand boiling points \nabove room \ntemperature.  They have their melting \npoint below room \ntemperature.  They have their \nmelting and boiling \npoints both below \nroom temperature.  \n7.  Intermolecular forces \nare very strong and \nconstituent particles are \nclosely  \npacked  Intermolecular forces",
  "Matter in Our Surroundings.txt\nmelting and boiling \npoints both below \nroom temperature.  \n7.  Intermolecular forces \nare very strong and \nconstituent particles are \nclosely  \npacked  Intermolecular forces \nare strong enough to \nkeep t he particles \ntogether but not strong \nenough to keep them in \nfixed positions.  Intermolecular \nforces are very \nweak and the \nparticles are free to \nmove.",
  "Matter in Our Surroundings.txt\nIllustration  \n5:\u2212 \na) Give two reasons why wood is a solid material.  \nb) \u2018A material has a known volume but no known shape.' Indicate if the \nsubstance is solid, liquid, or gaseous.  \nc) Describe the physical state of matter that can be squeezed readily.  \nd) \u2018A substance has both a defined shape and a defined volume.' Which \nphysical state d oes this statement represent?  A substance has neither a fixed \nshape nor a fixed volume. State whether it is a solid, a liquid or a gas.  \ne) Give two reasons to justify that:  \ni. Water is a liquid at room temp.  \nii. An iron almirah is a solid.  Class  IX Science    8 \n \n \n \n \n \n \nAns: a). Wood has  \n \ni.fixed s hape, and  \nii.fixed volume  \na) Liquid  \nb)  Gas  \nc) Solid  \nd)  Gas  \n \ni.Fixed volume but no fixed shape  \nii.Fixed shape and fixed volume.",
  "Matter in Our Surroundings.txt\n\u2022 Rigid and Fluid  \n\u27a2 Rigid is a word that denotes \"unbending\" or \"inflexible.\" Because it is  \nunbending or inflexible, a stone is stiff. Fluid is defined as \"a material that  \nflows easily\" and requires the use of a vessel (container) to keep it  \ncontained.  \n\u27a2 A solid is a kind of stuff that is unyielding. Solids have a tendency to keep  \ntheir shape when subjected to external force due to their ri gidity. As a  \nresult, rigidity is the primary distinguishing feature of solids.  As a result,  \nrigidity is the primary distinguishing feature of solids. Solids don't need  \nto be kept in a container.  Two common solids are a brick and a log of  \nwood.  \n\u27a2 A liquid is a fluid type of stuff that fills the container's lower half. Liquids  \nmust be kept in a container because they are fluids. Because liquids have  \na well -defined surface, they can be stored in an open container. The liquid  \nwill not spontaneously escape from th e open container. Water and milk",
  "Matter in Our Surroundings.txt\na well -defined surface, they can be stored in an open container. The liquid  \nwill not spontaneously escape from th e open container. Water and milk  \nare two prevalent liquids found in our environment.  \n\u27a2 A gas is a form of stuff that fills the entire container in which it is  \ncontained. Gases, like liquids, require a container to keep them contained.  \nBecause a gas has no open surface, it must be stored in a closed container.  \nIf a gas is kept in an open container, it will escape. Gases are frequently  \nstored in airtight gas cylinders because of this. Cooking gas (LPG), for  \nexample, is stored in airtight metal cylinders. We c an conclude from this  \ndiscussion that fluids include both liquids and gases. Fluidity is a property  \nof liquids and gases that allows them to flow smoothly. When exposed to  \nexternal stress, liquids and gases change shape quickly due to their  \nfluidity.",
  "Matter in Our Surroundings.txt\nClass  IX Science    9 \n \n \n \n \n \n \nIllustration  \n6:\u2212 Which of the following is rigid form of matter  \na) Alcohol  \nb) Ether  \nc) Love  \nd) Pen \nAns: Ether and alcohol  \n \n\u2022 Inter conversion of the state of matter  \nChanging the temperature, pressure, or both can cause matter to change its \nphysical condition.  \nA. Melting  is the transformation of a solid into a liquid.  \nB. Solidification is the process of turning a liquid into a solid.  \nC. The process of converting a liquid to a gas is known as vaporisation . \nD. Condensation  is the process of turning a gas into a liquid.  \nE. Sublimation  is the process of converting a solid to a gas.  \n \nNote: While increasing pressure in a gas will not change the physical condition \nof the gas, it will bring the particles closer together, causing the  gas to liquefy.  \nVaporization is promoted by lowering pressure over a liquid's surface.\n \n \nClass  IX Science    10",
  "Matter in Our Surroundings.txt\nClass  IX Science    10 \n \n \n \n \n \n \n \n \nIllustration  \n7:\u2212  When solid carbon dioxide is exposed to air, which of the \nfollowing factors is responsible for the change in state?  \na) Increase in pressure  \nb) Decrease in pressure  \nc) Increase in temperature  \nd) Decrease in temperature  \nAns: \n()a  Decrease in pressure; Increase in temperature  \n \n\u2022 Effect of change of Temperature and  Pressure   \nWe can change the physical condition of matter in two ways:  \nA. by changing the temperature; and  \nB. by changing the pressure  \nA solid can be changed to a liquid state by raising the temperature, and a liquid \nmay be converted to a gaseous state by lowering the temperature.",
  "Matter in Our Surroundings.txt\n\u2022 Melting  (Fusion )  \n\u27a2 Melting is the transformation of a solid substance into a liquid when it is  \nheated (or fusion).  \n\u27a2 Melting of the substance refers to the temperature at which a solid melts  \nand transforms into a liquid at atmospher ic pressure.  \n\u27a2 The heat energy in a solid substance causes its particles to vibrate more  \nvigorously. At the melting point, a solid's particles have enough kinetic  \nenergy to overcome the strong forces of attraction that keep them in fixed  \nClass  IX Science    11 \n \n \n \n \n \n \nplaces, and they bre ak apart into small groups. And the solid transforms  \ninto a liquid.  \n\u27a2 The greater the force of attraction between the particles of a solid  \nsubstance, the higher its melting point. The melting point of iron metal  \n,for ex ample, is extremely high (1535 degree c elcius ), indicating that the  \nforce of attraction between the particles of iron is extremely strong.",
  "Matter in Our Surroundings.txt\n\u2022 Boiling  (Vaporisation )  \n\u27a2 Boiling is the transformation of a liquid substance into a gas when heated  \nrapidly.  \n\u27a2 The boiling point of a liquid is the temperature at which it boils and  \ntransforms rapidly into a gas at atmospheric pressure.  \n \n\u2022 Condensation   \n\u27a2 When a gas (or vapour) is cooled sufficiently, the process of turning it to  \na liquid is termed condensation.  \n\u27a2 Condensation of steam occurs when steam (or water vapour) cools and  \nconverts to water (or condensation of water vapour).  \n\u27a2 It's the polar opposite of vaporisation. (Boiling)",
  "Matter in Our Surroundings.txt\n\u2022 Freezing   \n\u27a2 Freezing is the process of turning a liquid (solidification) into a solid  by \nchilling it, the reverse of melting.  \n\u27a2 When a liquid cools, its particles lose energy, slowing their movement.  \n\u27a2 If the liquid is sufficiently chilled (to the point of freezing), each particle  \nceases to move and vibrates in a fixed location. The liquid freezes and  \nsolidifies at this point.   \n\u27a2 As a result of the preceding discussion, we can conclude that changing the  \ntemperature can change the state of matter.\n \n\u2022 Effect of the change in Pressure on the state of matter   \n\u27a2 Short particles separated by smal l distances make up matter.  \n\u27a2 Interparticle distances are exceedingly short in the solid state.  \nClass  IX Science    12",
  "Matter in Our Surroundings.txt\n\u27a2 The inter -particle distances in liquids are slightly greater than in solids.  \n\u27a2 When compared to liquids or solids, inter particle distances are greatest in  \nthe gase ous state.  \n\u27a2 As a result, it can be shown that when pressure is applied to matter, the  \neffect on solids is insignificant because the particles are so close together.  \n\u27a2 In liquids, the effect of pressure will be minimal.  \n\u27a2 Because the inter particle distances are  vast, the effect of pressure on gases  \nwill be the greatest.  \n\u27a2 As a result, when pressure is applied to gases, the particles begin to move  \ncloser together. The attractive forces between the particles increase as the  \nparticles get closer together.  \n\u27a2 This rise in attracting forces aids the gas's transition of state. When enough  \npressure is applied, the attraction forces build to the point where the  \nphysical state transforms from gaseous to liquid.  \n\u27a2 The reverse can be expected to happen if the pressure on a g as is deceased.",
  "Matter in Our Surroundings.txt\nIllustratio n \n8:\u2212 Define melting process  \nAns: Melting is the transformation of a solid substance into a liquid when it is \nheated.  \n \n\u2022 Latent Heat   \n\u27a2 Heat that a substance needs to change its condition without increasing its  \ntemperature. It's called latent heat (hidden heat) because it's buried in the  \nsubstance undergoing a state transition and doesn't show up as a rise in  \ntemperature.  \n\u27a2  \u201cDuring a transition of state, the latent heat is used up in overcoming the  \nforce of attraction between the particles of the substance. It has no effect  \non the kinetic energy of the substance's particles. And since the  \nsubstance's temperature does not rise.\u201d  \n \nIllustration  \n9:\u2212 What is the latent heat of fusion of ice.  \nAns: \n53.34 10 / j kg\uf0b4   \n \n\u2022 Latent heat of  Vaporization and Fusion   \nThere are two types of latent heat:  \ni. Latent heat of fusion  \nii. Latent heat of vaporization  \n \n \n Class  IX Science    13",
  "Matter in Our Surroundings.txt\n\u2022 Latent heat of  Vaporization and Fusion   \nThere are two types of latent heat:  \ni. Latent heat of fusion  \nii. Latent heat of vaporization  \n \n \n Class  IX Science    13 \n \n \n \n \n \n \n\u2022 Latent heat of  Vaporization  \n\u27a2 The latent heat of vaporisation is the amount of heat in Joules necessary  \nto turn a unit quantity of 1 kg liquid into vapours without a temperature  \nchange.  \n\u27a2 Experiments have shown that it takes \n522.5  10\uf0b4  joules of heat to convert  \n1 kilogramme of water (at its boiling point,  \n100\u00b0C ) to steam at the same  \ntemperature. As a result, water's latent heat of vaporisation is \n522.5  10\uf0b4  \njoules per kilogramme (or \n522.5  10\uf0b4 J/kg).  \n\u27a2 \u201cIf the liquid freezes to create a solid and steam condenses to form water,  \nthe substance will emit an equal amount of latent heat of fusion and  \nvaporisation.\u201d  \n\u27a2 The Latent Heat of Vaporization varies depending on the substance.",
  "Matter in Our Surroundings.txt\n\u2022 Latent heat of  Fusion  (Solid to Liquid )  \nIt is the amount of heat in Joules required to transform one kilogramme of solid \ninto liquid form without causing a temperature increase.  \nExperiments have shown that to turn 1 kilogramme of ice into water at the same \ntempe rature (\n0\u00b0C ), \n53.34 10\uf0b4  J of heat is required.  \nSo, latent heat of fusion of ice is \n53.34 10\uf0b4  J/ Kg.  \nDifferent substances have different Latent Heat of Fusion .",
  "Matter in Our Surroundings.txt\nIllustration  \n10:\u2212 Why the temperature of melting ice does not rise even though \nheat is being supplied continuously.  \nAns: Because ice is a solid, its particles are attracted to one another by strong \nforces. These attraction forces keep the particles tightly packed in solid ice. The \nheat we give ice during melting is completely consumed by overcoming the \nforces of attraction between ice particles, causing them to loosen up and become \nliquid water.  As a result of this heat not increasing the kinetic energy of particles, \nno temperature rise occurs during the melting of ice. However, once all of the \nice has melted to create water, additional heating increases the kinetic energy of \nwater particles, causing the temperature of the water to rapidly rise.",
  "Matter in Our Surroundings.txt\n\u2022 Sublimation  \nSublimation is defined as the transformation of a solid into vapours on heating \nand back to a solid on cooling.  \nSolid Vapour (or Gas)\n  \n\u27a2 Ammonium chloride, iodine, comphor, naphthalene, and anthracene are  \nsome of the common substances that sublimate.  \n\u27a2 Solid carbon dioxide is yet another example of sublimation (which is  Class  IX Science    14 \n \n \n \n \n \n \ncommonly known as dry ice).  \n\u27a2 Carbon dioxide gas is formed when solid carbon dioxide (or dry ice)  \nsublimates.",
  "Matter in Our Surroundings.txt\ncommonly known as dry ice).  \n\u27a2 Carbon dioxide gas is formed when solid carbon dioxide (or dry ice)  \nsublimates.  \n \nIllustration  \n11:\u2212   \na) When heated, which of the following substances sublimates : \nI. Sugar  \ni.Urea  \nii.Ice \niii. Camphor  \niv. Sodium Cholride  \nv.Iodine  \nb) What happens to the heat energy that has been de livered once a solid  \nhas melted ?  \nc) A substance's melting point is lower than room temperature. Predict  \nthe state of its physical state .  \nd) Is it permissible to refer to ammonia in its gaseous state as vapours?  \ne) What is the name of the chemical reaction t hat converts a solid into a  \ngas? \nf) During a substance's change of state, which of the following energy is  \nabsorbed ? \ni. Specific Heat  \nii. Latent heat  \niii. Heat of solution",
  "Matter in Our Surroundings.txt\ng) Identify one common chemical that can change state when heated or \ncooled. . \nAns:  \na) Camphor and iodine  \nb) It is converted into latent heat of fusion  \nc) It is a liquid.  \nd)  No, it is not  \ne)  It is called sublimation  \nf)  Latent heat  \ng) Water  \n \n\u2022 Evaporation  \n\u27a2 The phenomena of evaporation  occurs when a liquid transforms to a  \ngaseous state below its boiling point.  \n\u27a2 Water molecules are attracted to other water molecules in all directions,  Class  IX Science    15",
  "Matter in Our Surroundings.txt\nbut the water molecules near the surface of water are only dragged inward,  \nwhich is below the water's sur face.  \n\u27a2 Note: Evaporation is a phenomena that occurs in all liquids in theory. But,  \nin general, when we talk about evaporation, we're talking about water  \nevaporation.  \n\u27a2 Vapour  is a substance that can remain in a gaseous state at a temperature  \nwhere it would ordinarily be a solid or liquid.  \nExamples of solids that can exist as vapour: camphor, naphthalene",
  "Matter in Our Surroundings.txt\n\u2022 Factors Affecting Evaporation  \nEvaporation depends on temperature, surface area and weather conditions  \na) As the quantity of water molecules at the surface grows, evaporation  \nincreases if the surface area of the water is big. As a result, more water  \nmolecules are likely to break out once they have enough kinetic energy.  \nb) As the temperature approaches the boiling point of water, evaporation  \nincreases. The kinetic energy of the molecules increases as the  \ntemperature rises. The extra kinetic energy required by surface molecules  \nto break loose or evaporate is reduced as a result. As a result, evaporation  \nincreases.  \nc) Evaporation decreases in excessively humid weather because the air is  \nsaturated with water molecules.  \nd) As water evaporates, the air just above the water surface becomes  \nsaturated with water molecules.",
  "Matter in Our Surroundings.txt\nIllustration  \n12:\u2212  What effect does temperature and surface area have on \nevaporation?  \nAns: Evaporation increases as the temperature and surface area increase.  \n \n\u2022 Cooling  Effect   \nHow Does Evaporation Cause Cooling?  \nWhen a liquid evaporates, the energy is extracted from the liquid. As a result, it \ncontinues to cool. The liquid absorbs the energy lost by the surroundings, \ncausing them to cool. During the summer, for example, air coo lers are used to \nprovide forced cooling.  \n \nIllustration  \n13:\u2212  Make a note of the cooling mechanism.  \nAns: As a gas particle's energy drops due to cooling, the particle's moment slows \ndown. The particles also become significantly closer to one another, resulting in \nthe intermolecular attraction force. The gas contracts as a result of this."
]