DR ZAKIR HUSSAIN MEMORIAL BHARATIYA VIDYA VIHAR TALENT DEVELOPMENT PROGRAMME: 2014

CLASS 6 Science : Cleaning of food or Separation of Substances solved question

Q. What is substance?

Ans: A kind of matter that cannot be separated by physical methods.

Q. What is pure substance?

Ans: Clean and diseases free substance are called pure substance.eg. elements.

Q. what is matter?

Ans: Everything around us having mass and volume is called matter. it is of three types element compound and mixture.

Q. What is compound?

Ans: Ans: The substance containing two or more types of substance mixed together in fix ratio is called compound.eg salt, sugar and water

Q. What is mixture?

Ans: The substance containing two or more types of substance mixed together in any ratio is called mixture.eg. air , food grain, milk, sea water. A mixture can be separated by physical methods.

Q. Give two properties of mixtures.

Ans. (i) The ratio of their constituents is not fixed.
(ii) Mixtures do not have definite melting point or boiling point.

Q. Why we need to separate mixture?

Ans: The following are the reasons for the separation:

(i) to remove the undesirable constituents from mixture. (ii) To obtain desirable substances from mixture. (iii) To obtain highly pure substance.

Q. What is Chaff or husk?

Ans: the debris arising from agriculture processing of food grain like maize, rice wheat is called chaff.

Q. Differentiate between hand picking & winnowing.

Ans. Hand picking: the process of cleaning mixture by picking out with hand.

It is used when the constituents of the mixture are big in size & visibly differently .For example: separating stones from rice.

Winnowing: The process of cleaning mixture like husk from grain with the help of wind which blow lighter husk.

It is used when one of the constituents is lighter and the other is heavier, For example: shaff from grain.

Q. Define sieving

Ans: The process of separating fine lighter particles from larger particles using sieve. Eg husk, gravel, dust ,tea leaves etc .

Size of the holes of sieve or mash depends on the size of particles separated.

if the solid mixture is stirred or shaken on a mesh. Particles smaller than the holes of the mesh fall & the bigger ones remain on the mesh.

Q. what is sedimentation and decantation?

Ans: The process of separating heavier insoluble solid particles mixed in liquid. For separating we left mixture u disturbed for some time. The heavier particles settle down at bottom is called sediment.

The method of collecting clear liquid from sediment is called decantation.

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CBSE 6th Science : Separation of Substances solution

EXTRA QUESTIONS

Q. What is solution?

Ans: A solution is a mixture of two or more substance so that properties are the same throughout . The substance in large quantity is called solvent and The substance in small quantity is called solute.

Q. What is saturated solution?

Ans: if solvent cannot dissolve more solute at room temperature is called saturated solution. A solution is said to be unsaturated as long as more solute can be dissolved.

Q6. State the method used for separating following mixtures:

a) Separating iron from sulphur magnetic separation

b) Separating oil from water decantation

c) Chalk from water filtration

d) Bran from flour sieving

e) Pulses from rice hand picking

Q. How fat separated from milk?

Ans: Centrifugation or churning method. The method separation involving high speed is called churning using centrifuge machine.

Q. Name process of separating husk from grain?

Ans: winnowing

Q. How can you turn water vapour into water

Ans: On cooling called condensation.

Q. what is condition in which no more solute can dissolve in the solvent?

Ans: Saturated Solution

Q. What is the left over material known as?

Ans : Residue

Q. By which process you get flour from husk?

Ans: Sieving

Q. How do you clean grain at home ?

Ans: Hand picking and Sieving

Q. name the part of plant in which grains are embedded ?

Ans: Cob

Q. What is the method in which heavier particle allow to settle down?

Ans: sedimentation

Q. How are stone and pebble are separated on construction site?

Ans : by using sieve called Sieving

Q. How do you carry out churning?

Ans: By rotating solution rapidly.

Q. How Chaff or husk is separated from grain after harvesting?

Ans: It is separated by threshing using thresher.

Q. Explain the method of obtaining common salt from sea water.

Ans. Sea water is collected in shallow pits dug on the sea shore. The heat of sun evaporates water. When enough water has evaporated the solution becomes concentrated, then the salt begins to crystallize.

Q. what is thresher and why it is called an efficient machine ?

Ans: thresher is a machine that separate husk from grain. It can remove husk ,dusk and produce neat and clean food grain so it is called an efficient machine .

Q.Fill up the blanks :

(1) The method of separating seeds of paddy from its stalks is called ................... .
(2) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. Thisprocess of separating cream from milk is an example of ................... .
(3) Salt is obtained from sea water by the process of ................... .
(4) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ....................

Ans. (1) The method of separating seeds of paddy from its stalks is called threshing.

(2) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. Thisprocess of separating cream from milk is an example of filtration.

(3) Salt is obtained from sea water by the process of evaporation .

(4) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called decantation.

TEST PAPER 1

CLASS– VI : SEPARATIONS OF SUBSTANCE

CLASS– VI ASSIGNMENT SEPARATIONS OF SUBSTANCE
Q.1 What is separation?

Q.2 Why the separation of substances is necessary?

Q.3 What is the basis of separation of components of mixture?

Q.4 When do we use hand picking as the method of separation?

Q.5 What is threshing? How is it done?

Q.6 Define winnowing? What is the principle of using winnowing as method of separation?

Q.7 Where do we find sieving as the method of separation?

Q.8 You are given a mixture of sand, salt and iron filling. Suggest some methods for separating all the components of this mixture?

Q.9 Define filtration? Give 3 examples where filtration method is used.

Q.10 What is evaporation? Where do we use this method at home?

Q.11 What method is used to separate salt from sea water and how?

Q.12 In which cases handpicking is enough as a method of separation?

Q.13 One method of separation is not enough. Comment.

Q.14 Differentiate between a pure substance and a mixture.

Q.15 Is the separation of two immiscible liquids using separating funnel same as decantation?

Q.16 What do you use to remove discarded tea leaves from tea?

Q.17 What impurities are present when you buy wheat, rice or pulses from the market?

Q.18 What is the process called when stem of plants (stalks) are beaten to separate grains?

Q.19 What process is used to separate light solid particles from heavier solid particles?

Q.20 What will settle down when mud and rice are added to water?

Q.21 What is the process called when strainer or filter funnel is used?

Q.22 What is a solution called which contains the maximum amount of dissolved solute?

Q.23 How do you separate a light liquid from a heavier liquid?

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Shorting of material into group class vi science

6th CBSE Science Material of Daily Use/Shorting of material into group
· The word material is related to things that are around us.

· Matter is any abject around us that occupy space and has mass

· Matter can found in around us in three state Solid , liquid and Gas

· In solid state, particles of matter are tightly packed and having no gap between them. Due to this reason Solid have definite shape and volume.

· In liquid state , particles of matter are loosely packed together have some space between then .due to this reason liquid have fix volume but no fix shape .

· In Gas particles of matter are far from each other due to this gas have no fix volume and shape.

· Both liquid and gas are called fluids as they can flow due to weak force of molecular attraction between particles.

· We have large numbers of material around us and we need to know about their properties. To make study of the nature of different substance easy we have to divide it into group.

· Shorting of material into group on the basis of similarity of different substance is called Classification.

· Material around us classified on the basis of their properties:

(a) Appearance or luster (b) Hardness or softness (c) Solubility

(d) Floatation (e) Transparency

(f) Conductivity of heat and light (g) Combustibility (h) Magnetism

Q. What is luster?

Ans: Materials around us have a particular type of shine called Luster like gold, silver, aluminum etc

Q. Some metal can hammered into thin sheet without breaking into pieces. Name this property of metals?

Ans: Malleability.

Q. Some metal drawn into thin wire. Name this property of metals? Ans: Ductility.

Q. Name material used to make chalk? Ans: Calcium carbonate

Q. Why do houses have cement floor?

Ans: Houses have cement floor because it can polished to make attractive.

Q. Define soluble and insoluble substance?

Ans: Material that mixed with water is called soluble e.g. acid, base, milk, lemon juice, sugar and alcohol. Material that do not mixed with water is called insoluble like oil, sand, alum etc

Q. what will happen if you drop piece of chalk and sponge in to glass of water?

Ans: Chalk and sponge absorb water due to gap between their particles.

Q. Which material you prefer to use for furniture?

Ans: Wood and Metal as they can polished and hard to break.

Q. Classify material on the basis of conductivity?

Ans: Materials have property to conduct electricity through them. This property is called conductivity. On the basis of that it can be divided into Good conductor and bad conductor.

A substance which conducts electricity is called good conductor like silver, copper, aluminum.

Q. Name the best conductor metal? Ans: Silver is best conductor.

Q. Name a non metal that conduct current? Ans: Graphite is only non metal that conduct electricity.

Q. What is the name of material that can scratch easily? Ans: hard

Q. Name hardest and softest substance
Ans: Diamond and talcum powder

Q. What does cold drink contains.
Ans: carbon dioxide gas, sugar and flavored syrup.

Q.Why axe head is made up of iron?

Ans: Because iron is cheap, hard and malleable.

Q. Defines: Solute, solvent and solution?

Ans: Solution: The mixture of two or more substance is called solution. Solute: A substance that is being dissolved is called Solute. Solvent: The substance in which solute dissolve.

Q. Why ice floats on water?

Ans: The density of ice is lower than water so, Ice floats on water.

Q.What is transparency?

Ans: The property of substance to allow light to pass through is called transparency.

Q. What is Opaque object?

Object that do not allow light to pass is called opaque like wood, metals etc.

Object that allow light to pass partially is called Translucent. Glass, water, Oil paper etc.

Q. Why handle of utensils made up of Plastic or wood?

Ans: because Plastic or wood

Q. What kind of substance do we see around us?

Ans: we have two types of substance like man Plastic or wood made and natural.

Q. Why do some substance sink or others floats to the beaker field with water?

Ans: Some substances do not dissolve in water so they float unless sink.

Q. Why we can smell something e.g. perfume?

Ans: we can smell something e.g. perfume because smell the liquid floats in the air when evaporated.

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Science Class VI: Fibre to fabric

SCIENCE CLASS-VI ASSIGNMENT FIBRE TO FABRIC

Q 1 Fill in the blanks:-

a) A fabric is made up of______________ arranged together which are further

made up of --------------.

b) Fibres obtained from plants and animals are called______________.

c) ____________ and _________ fibres are obtained from plants.

d) W ool is obtained from the fleece of __________ and ___________.

e) Silk fibre is drawn from ___________ of silk worm.

f) ____________ and _______________are examples of synthetic fibres.

g) Jute is obtained from the____________ of the jute plant.

h) The process of making yarn from fibres is called____________.

i) Weaving of fabrics is done on ___________ which are hand operated or power operated.

Q2 Name the following:-

i) Mahatma Gandhi popularized the use of this device

ii) Device used for spinning

iii) The season in which jute is cultivated.

iv) Part of the cotton plant from which cotton is obtained.

v) Two ways by which fabrics are made from yarns.Q3 Classify the following fabrics as cotton ,wool, silk or synthetics:- Bed sheets , blankets,curtains,table cloths, towels, school bags, gunny bags and dusters

Q4 What kind of soil and climate is needed for growing cotton?

Q5 Hare cotton fibres collected from the cotton plant?

Q6 Name some places where cotton is grown in India

Q7 Name some states in India where jute is grown?

Q 8 Explain the process of ginning.

Q9 Differentiate between weaving and knitting.

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CBSE_NCERT_6th science study material: Chapter: Habitat

1. Q. What is habitat?

Ans: A place where living things live naturally is known as habitat (Home). For example:

(i)Aquatic habitat refers to the water where plants and animalssurvive like pond, river, sea (in water),

(ii) Terrestrial habitat: It refers to the land where all plants and animals survive. It includes deserts, forests and grasslands, as well as coastal and mountain regions

2. Q. What are the Components (Parts) of Habitat?

Ans: There are two main components of habitat

(a) Biotic Components: Living things present in a habitat are called biotic component like plants , animals and micro organism.

(b) Abiotic Components: All the non-living things present in a habitat is called abiotic components like air water soil rocks, sunlight and heat etc.

3.Q. How biotic and abiotic components depend on each other?

Ans: Biotic and abiotic components in a habitat depend on each other for survival for example plants need sunlight and for photo synthesis and animal need oxygen for respiration.

4.Q. Why are green plants called producers?

Ans: Because plants provide food to all animal and non- green plants

5.Q. Why are non-green plants animals are called consumers?

Ans: Because non-green plants animals are directly or indirectly eat food prepared by plants.

6.Q. How do scavengers help to clean environments?

Ans: Scavengers are those animals that feed (eat) on dead animals or plants and help to keep environment clean.

7.Q. Why micro organisms are called decomposers?

Ans: A very tiny living organism that cannot be seen by necked eyes is called micro organisms like bacteria and fungi.

Micro organisms feed on dead and decaying organic matter and break them into nutrients that are used by plants so they are called decomposers.

8. Q. what is photo tropism?

Ans: Plants and animals show movements towards light is called photo tropism. Shot move towards light called positive photo tropism and root move against light called negative photo tropism.

9. Q. What we call animal that are active during night ?

Ans: Nocturnal like owl, bat, cockroach etc.

10.Q. Which bacteria help to use nitrogen fixed in soil to plants?

Ans: Rizobium

11.Q.What is adaptations?

Ans: Living organism modifies themselves according to different types of habitat called adaptations.

12. Q. Distinguish between herbivores and carnivores?

Ans: Herbivores feed on plants where as carnivores feed on flesh of other animals.

13. Q. State any two flight adaptation in aerial animals?

Ans: (i) Having streamline body shape that protect from wind

(Ii) Having hollow bones called pneumatic bones

14.Q. How does temperature affect plants and animals?

Ans. (i) Leaves and stem of plants wither (ii) Skin change into dark colour (iii) Affect size ofanimals

15.Q. What is the role of light on plants?

Ans: (i) Help in photosynthesis (ii) Help in fruit and flower developments (iii) Help in growth of plants

2. Q. Distinguish between herbivores and carnivores?

Ans: Herbivores feed on plants where as carnivores feed on flesh of other animals.

13. Q. State any two flight adaptation in aerial animals?

Ans: 1.Hhaving streamline body shape that protect from wind

2. Having hollow bones called pneumatic bones

14.Q. How does temperature affect plants and animals?

Ans.
(i) Leaves and stem of plants wither

(ii) Skin change into dark colour

(iii) Affect size of animals

15.Q. What is the role of light on plants?

Ans:
(i) Help in photosynthesis

(ii) Help in fruit and flower developments

(iii) Help in growth of plants

16. Q.What types of adaptation seen in desert habitat?

Ans: (i) store water in body (ii) Use less water to survive

(iii) Keep away from hot place (iv) live in deep borrow

17.Q. How biotic and abiotic components depend on each other?

Ans: Plants depends on sunlight and air for food. Animal depends on air and water for to live. Decompose dead part of living organism and convert into organic matter that develop soil fertility. Plants also maintain purity of atmosphere.

18. Q. What is the difference between a predator and a prey?

Ans: A predator is an animal that eats other animal, whereas a prey is an animal that is eaten by a predator.

19. Q.How is a cactus adapted to survive in a desert?

Ans: cactus has a waxy surface to store water. It also has thorns to reduce loss of water. It also have thick, fleshy stem.

20. Q. What is acclimisation?

Ans: Small changes that take place in body of single organism over short period to overcome the small problems due to change in surrounding is called acclimisation.

21. Q. Give reasons: Why are deep sea worms blind?

Ans: As we move deep into seas and oceans the amount of light or the visibility decreases. Deep sea worms are blind because of the lack of requirement. Some worms have large eyes but those are not for the purpose of seeing . These worms have developed strong sense of smell to encounter these problems.

22. Q. Give reasons: Why are some marine creatures living in the deep sea give out light of thereof own?

Ans: Since there is lack of light in deep seas, some organisms can give out light to assist them in finding their way in the dark.This also helps them in finding prey to feed on and can also be used to find a mating partner.

23. Q. Give reasons: Why the upper surface of the leaves of lotus have a thick cuticle ?

Ans: Lotus is an aquatic plant. The leaves of the lotus plant have a thick waxy cuticle that helps in repelling water and keeps the stomata open so that water transport occurs effectively in plant.

24. Q. why do cockroaches hide as soon as the light is switched on?

Ans: Cockroaches cannot tolerate the high intensity light as they have some light receptors in their eyes.

25. Q. Give two examples of non-living things which show any two characteristics of living things.

Ans: Non-living things such as clouds grow in size and also move from one place to another. Another non-living thing that shows two of the characteristics of living things is a car which needs fuel (food) to function and also moves from one place

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6th Chapter _Living things and surrounding: Objective formative questions(MCQ's)

Fill in the blanks : Chapter:Habitat
(i)In the sea plants and animal surrounded by -------------------------(saline water)

(ii) The place where living beings live is called their -------------(Habitat)

(iii) In Cactus plant, ---------------are reduced to spines (Leaves)

(iv) Global warming increases the concentration of ------in the atmosphere(carbon dioxide)

(v) ------------are examples for Decomposers (Bacteria and fungus)

(vi) Living component of a habitat is called as -------------- (Biotic)

(vii) Anything which produce and response in an organism is called as -----------(Stimulus)

(viii) A potted plant is kept in a card board box with a small slit of sun light exhibits ----- Movement
Phototrophic)

(ix) If we blow through lime water it turns milky. This proves that exhaled air contains ------ (carbon
dioxide)

(x)-------- are plants that grow in dry desert area (Xerophytes)

(xi)--------- are plants that grow in moist area (Mesophytes)

(xii) )--------- are plants that grow in soil rich in salt (helophytes)

(xiii) ---- help in pollination and seed dispersal (wind)

(xiv)--------- are plants that best grow in full sunlight (heliophytes)

(xv) --------- are plants that best grow in low sunlight (sciophytes)

(xvi) Roots are ---------------phototropic (negatively)

(xvii) Earthworms breathe through their ---------------( moist skin)

(xviii) ------are those animals which can live on land and also in water (Amphibians)

(xix) ------ is an example of a non moveable animal .( coral)

(xx) -------are those animals which lay eggs example- crow, lizard (Oviparous)

(xxi) -------are those animals which do not lay eggs & give birth to young ones for example- lion, dog.
viviparous)

(xxii) ---------- habitat comes under aquatic habitat (Marine)

(xxiii) _________are certain changes in the surroundings that cause an organism to respond to them. Stimuli)

(xxiv) -------------- help aquatic animal to float in water { Aerenchyma (air spaces in their bodies)}

(xxv) Some fungi grow in soils of burnt areas called -----------------. (Pyrophilous)

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Class VI Physics: Chapter: Electrical circuit

Quest Time CBSE NCERT VI Chapter: Electric currents, Circuits, Cell.

1. From where do we get electricity?

Ans: A power station provides electricity. If the supply of electricity may fail we use other sources of energy like torch at home.

2. Why does the bulb glow switch on a torch?

Ans: It glows because the electric energy stored in the electric cells is converted into light energy by the bulb.

Hence Electric cell is a source of light energy.

3. Name the scientist who developed first Cell?

Ans: The first electric cell was developed by an Italian scientist Luigi Galvani and then improved by Alessandro Volta.

4. Name a cell that is recharged by Light of The Sun?

Ans: alkali cells and solar cells. Solar cells convert light energy into electric energy.

5. What is an electric cell?

Ans: An electric cell is a device which converts chemical energy into electric energy.

The cell has two different metal plates – one is the positive terminal and the other is the negative terminal. These plates are kept inside a chemical called electrolyte. One of the chemical is white in color NH₄Cl (Ammonium chloride) and other is a black powder MnO₂ (manganese dioxide).

6. What is an electric current?

Ans: Electric current is the flow of electrons or charge. The cell is a source of electric current.

7. What is an electric circuit?

Ans: An electric circuit is the closed path along which electric current flows from the positive terminal to the negative terminal of the battery.

A circuit generally has:

a) A source of electric current - a cell or battery(A group of cell called battery)

b) Connecting wires for carrying current.

c) A device which uses the electricity - a bulb ( Bulb is a device that convert electrical energy into light)

d) A key or a switch – A component of circuits that stop or allow the flow of current. When the current flows the circuit is said to be closed circuit. When the current does not flow, the circuit is said to be open circuit.

8. How does a bulb glow and produce light?

Ans: Inside the bulb there is a thin coil of wire made of tungsten, called filament. It gets heated and glows when the current flows. Hence, electric energy is converted into light energy by a bulb.

9. If the filament inside the bulb is broken will the bulb glow? Why?

Ans: The circuit is not complete; current does not flow through the circuit and the bulb does not glow.

10. Why do we feel warm when we touch the lighted bulb?

Ans: The bulb also emits heat energy along with light.

11. What conductors and insulators?

Ans: The materials which allow electric current to pass through them are called conductors. Examples: All metals like Copper,Iron, Silver and Human body.

INSULATORS: The materials which do not allow electric current to pass through them are called bad conductors or insulators. Examples: Plastic, Wood, Rubber and Glass.

12. Why do electricians wear rubber gloves and shoes while at work?

Ans: It because rubber gloves are an insulator and prevent current to flow in body .Thus saves electricians from electric shock.

13. What do you mean by heating effect of current?

Ans: Electric current is actually the flow of electrons in the conducting material. Now,

when these electrons flow, they encounter some resistance in the structure of the conductor, which accounts for the "resistance" of materials. As the electrons collide or vibrate, heat energy is generated depending on the resistance of the conductor. This overall effect is called heating effect of electrical current.

14. Name a few appliances that work on the heating effect of current?

Ans: Electric kettle: Used for boiling water to make tea or coffee

Electric bulb : The filament of the bulb is heated when current flows and becomes white hot to emit brilliant light.

Electric iron: Used for ironing or pressing clothes.

Electric toaster: Used to toast bread

15. Name a special material used for heating component?

Ans: It is a coil of wire made of a special material called nichrome which becomes very hot when current is passed. This heat is used to cook food (as in an electric stove), heat water ( as in an electric kettle, electric heater) etc

16. Name the elements used to make an alloy nichrome?

Ans: Nickel and Chromium.

17 Why are electric wire are made up of copper through silver is best conductor?

Ans: Silver is an expensive metal. Material needed for conductor should be cheap as wires are used extensively in almost every appliance. That is why silver can't be used to make wires.

18. Why do you apply a tap over the joint of electric wire?

Ans: Tap is an insulator and save us from electric shock.

19. If you connect a battery cell to the bulb through a wooden stick, the will not glow. Why?

Ans: No, wooden stick is an insulator that cannot conduct electricity

20. Do not handle the electric appliances when your hands are wet. Why?

Ans: Tap water is good conductor and we may get electric shock.

21. There will be three colored wires normally used while connecting any electric equipment. What are those colors? Tell which coloured wire gives us electric shock?

Ans: Red (Live wire that give us electric shock), Black (Neutral) , and Green(Earth wire)

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CBSE_NCERT Class 6th Chapter-Waste (Garbage In, Garbage Out )

CBSE 6^th Chapter -Waste (Garbage In, Garbage Out )

• Introduction

• Segregation of wastes

• Management of biodegradable wastes

• Composting, Landfills - Structure of a landfill

• Management of Non-Biodegradable Wastes

• Reduce, Reuse, Recycle - Recycling of Plastics,
Recycling of paper

Garbage Disposal

A large, low-lying area used to dispose garbage is known as a dump.

A garbage dump is also used as landfill. Garbage collectors collect waste and then dispose it at
garbage disposals.

Garbage dumps have flies, cockroaches and mosquitoes, and later turn into breeding grounds for micro-organisms that may cause diseases. That is why these garbage dumps are usually located on the outskirts of a city.

Components of garbage: Garbage has useful and non-useful components.

ü Useful garbage components are those that can be decayed easily. The process ofdecaying is known as
composting. Useful garbage components are fruit and vegetable waste, plant and animal waste, tea leaves, coffee grounds and paper. These useful components of garbage are converted into manure in the soil.

ü Non-useful garbage components include polythene bags, plastics, glass and aluminum foils. These take longer to decay. Decaying of these non-useful components is known as decomposition. When non-useful components decay, they release harmful gases that damage the environment. To avoid the adverse impact, these garbage items are sent for recycling. For example, when leaves burn, they release harmful gases and causes air pollution. Moreover, they lead to asthma and lung diseases. That is why leaves should be buried so as to convert them into manure.

ü Vermicomposting

The process of preparing compost with the help of red worms is called vermicomposting. The red worm is a type of earthworm that lives in the soil rich in organic matter, which is a combination of nitrogen-rich and carbon-rich material with plenty of moisture and microbes.

Method of Vermicompositing

A vermicomposting pit is made with a wooden box or big cement rings. A mesh is spread at the bottom of the pit. Vegetable waste, fruit waste, waste paper which is not shiny or coated with plastic, is spread over the mesh. Water is sprinkled to create moisture so that the red worms can live. A vermicomposting pit takes nearly two to four weeks to completely convert waste into manure.

Waste material that is rich in oils, salt, meat and vinegar stops the growth of red worms. These red worms have a special structure called gizzards with which they grind food material. A red worm eats food equal to its weight every day. Red worms do not survive in too hot or too cold conditions.

Recycling Paper and Plastics

It is important to reuse things than discarding them as waste. Industries use recycled or waste paper to regenerate paper. Paper that is suitable for recycling is called "scrap paper". You can recycle old newspapers, magazines, notebooks and used envelopes, but not waxed paper, oil-soaked paper, paper contaminated with food, carbon paper, thermal fax paper, plastic laminated paper, stickers, and sanitary products or tissues.

Steps involved in recycling paper

ü Tear paper into small pieces.

ü Soak these pieces in water for a day.

ü Make a thick paste and spread it on a net or sieve.

ü Let water drain off completely

ü Use an old cloth or newspaper to remove the extra water from the paste and dry it.

ü Use this paste to get beautiful patterns.

Disadvantages of using of polythene bags

We use many plastic items such as tooth brush, combs, containers, bottles, shoes, toys, wires, frames and bags every day but using plastic is very harmful in terms of health and as well as the environment. Plastics are not suitable for storing cooked food because they emit harmful chemicals when they are exposed to high temperatures. Using plastics causes health problems such as heart disease, diabetes and reproductive dysfunction.

Harmful gases are emitted from burning plastics, which cause cancer and they kill living beings. That is why plastics should be disposed in the right way.

Plastics thrown casually get into drains and sewages, often blocking the way and causing water-logging. So polythene bags should not be used for garbage disposal.

Measures taken to prevent from the dangerous effects of plastics:ü  Reduce, reuse and recycle plastics.
ü  Carry jute or cloth bags for shopping
ü Do not store food items in plastic bags.
ü  Do not burn plastic items.
ü  Recycle plastics so that new plastic items can be made.
ü  Waste that does not decompose should be put in blue dustbins, while waste that decomposes easily should be put in green dustbins.

Vermicomposting

Conversion of the waste generated in the kitchen into organic matter with the combined action of earthworms and micro-organisms is called vermicomposting . The organic matter so formed is used as manure for plants

VI – SCIENCE WORKSHEET: Garbage In, Garbage Out

I. Fill in the blanks :

1. Method of making compost using _____________ is called vermin composting

2. Converting plant and animals wastes into manure is called ____________.

3. ____________ is an area where the garbage is collected.

4. We need to generate ____________ waste.

II. True or False Sentences :

1. Paper can be recycled to get useful products.

2. Drains get choked due to plastic thrown by us.

3. Plastics are eco-friendly.

4. Redworms eat up on green leaves on trees and make compost.

5. Plastics give out harmful gases up on heating or burning.

III. Answer these Questions

1. How do earthworms increase fertility of soil?

2. Rag pickers always suffer from diseases why?

3. Why does composting of leaves better than burning them?

4. Why should plastic food containers be avoided?

5. Why we should not throw away any things that can be recycled?

6. Why recycled plastic are not recommended for storing food in?

8. What is waste management and why it is so important?

9. Which garden worm generally used for Vermi composting.

10. Why worm box aerated in the process of vermi composting?

DR ZAKIR HUSSAIN MEMORIAL BHARATIYA VIDYA VIHAR TALENT DEVELOPMENT PROGRAMME

Monday, 22 December 2014

class 6 maths

CLASS 6 Science