Science - Class 6

Chapter - 1

Source of food

1:- Write four functions of food.

Ans:- The four functions of food are

1-It provides energy to do work and other functions.

2-It helps in the growth of our body.

3-It helps in healing injuries and protects our body from diseases.

4-It keeps our body warm.

2:- How many sources of food? Name them.

Ans:- There are two types of sources of food.

1-plants

2-animals

3:- What are producers?

Ans:- Green plants produce their own food. Hence they are called producers.

4:- What are consumers?

Ans:- Animals donot produce their own food. They obtain their food from plants and other sources. So they are called consumers.

5:- Write six plants whose roots are eaten by us.

Ans:- Carrot, radish, turnip, sweet potato, beetroot, cassava

6:- Write two plants whose stems are eaten by us.

Ans:- sugarcane, kamal kakdi (stem of lotus)

7:- Write six plants whose underground stems are eaten by us.

Ans:- Potato, corms, alocasia, colocasia, ginger, and turmeric.

8:- Write a plant whose leaves are used as salad.

Ans:- Lettuce

9:- Write six plants whose leaves are eaten by us as vegetables.

Ans:- cabbage, spinach, fenugreek, chenopodium, amaranth, and mustard leaves

10:- Write two plants whose leaves are used for their flavour and medicinal value.

Ans:- mint, coriander

11:-Write four plants whose flowers are eaten by us.

Ans:- Cauliflower, broccoli, banana, bauhinia

12:- Write a flower whose petals are used for making jam, and also as medicine.

Ans:- Rose

13:-Write five seeds that are rich sources of flour.

Ans:- corn, barley, oat, millets, rice

14:- What is pulse?

Ans:- A pulse is the broken half of bean seeds.

15:- Write five pulses name

Ans:- pea, gram, lentil, pigeon pea, chick pea

16:- Write some seeds by which we extract edible oils.

Ans:- mustard, soya, groundnut, sunflower, cocount, olive

17:- Write two edible fungus which is full of protein.

Ans:- mushroom and morchella

18:- Write five food items that we get from animals.

Ans:- Milk, eggs, meat, chicken, fish, honey

19:-write five name of milch animals.

Ans:- cow, buffalo, goat, sheep, camel

20:- Write short notes on milk.

Ans:-Milk is a complete food. It is rich in proteins and calcium. Milk is deficient only in fibres and vitamin C. Milk is good source of butter, cheese, curd, ghee etc.

21:- Which nutritions do we get from egg?

Ans:- We get proteins and minerals from egg.

22:- Write five animals that give us meat.

Ans:-goat, sheep, birds, fish, wild animals

23:- How many types of animals according to eating habits?

Ans:-There are three types of animals according to their eating habita

1-Herbivores

2-Carnivores

3-Omnivores

24:- What is herbivores?

Ans:- Those animals that eat only grass and leaves are called herbivores.

For example:- cow, buffalo, sheep etc.

25:- What is Carnivores?

Ans:- Those animals that eat only flesh of other animals are called carnivores.

For example:- tiger, lion, cheetah etc.

26:- What is omnivores?

Ans:- Those animals that eat both plants products and other animals are called omnivores.

For example:- crow, bear, dog, cat etc.

27:- What is the main food of southern India?

Ans:- Rice and curry

28:- What is the main food of northern India?

Ans:- roti, dal and rice

29:- What are scavangers?

Ans:- Animals that consume dead and decaying food from surroundings and help in keeping the surrounding clean is called scavangers.

For example:- vulture, crow, hyena etc.

 

 Components of food, chapter-2, class-6

 

 1:-What are nutrients?

Ans:- The components of food which help our body in growth, maintaining life and to fulfill different needs of the body are called nutrients.

2:- Write the name of five primary nutrients.

Ans:- carbohydrates, fats, proteins, vitamins and minerals

3:- Who is also known as energy giving nutrients?

Ans:- Carbohydrates and fats

4:- Who is also known as body building food?

Ans:- Proteins

5:-Who is also known as protective nutrients?

Ans:- Vitamins and minerals

6:- Write the name of two elements that is not a nutrients but the important part of food. They are called supplements.

Ans:- Fibres and water

7:- Write short notes on carbohydrates.

Ans:-Carbohydrates is an important nutrients of our food. Carbohydrates provode energy to our body. It provides quick energy to our body which helps in doing work and keeps our body warm. There are two types of carbohydrates

1-sugar

2-starch

8:- Write short notes about sugar.

Ans:- Sugar is a simple carbohydrate. There are five types of sugar

1-glucose

2-sucrose

3-fructose

4-lactose

5-maltose

9:- What is sucrose?

Ans:- Sucrose is a type of sugar that we get from sugarcane juice. The sugar which we add to our tea, coffee, cake and puddings is sucrose.

10:- What is fructose?

Ans:- Fructose is a type of sugar that we get from juicy fruits like orange, apple, mango etc. It is the combination of glucose and sucrose.

11:- What is lactose?

Ans:- Lactose is a type of sugar that we get from milk.

12:- What is maltose?

Ans:- Maltose is a type of sugar that we get from fermented starch like wine.

13:- What is glucose?

Ans:- Glucose is the simplest of all the sugars and immediayely taken into the blood from the food canal.

14:- Write short notes on starch.

Ans:- Starch is a complex carbohydrate. It comes from cereals like rice, wheat and in vegetables like potato and sweet potato. Starch is used in the preparation of bread, loaf, buns, cakes and other items.

15:- What are the fats? Give example

Ans:- Fats are the energy giving nutrition. They are two times reacher in energy then the same amount of carbohydrates. They are normally solid at room temperature..

For example:-  pure ghee, butter, cream, cheese, meat

16:- What are oils? Give example

Ans:- Oils are unsaturated fats which are normally liquid at room temperature.

For example:- mustard oil, sesame oil, sunflower oil etc.

17:- What is the difference between fat and oil.

Ans:- fats are solid at room temperature but oils are liquid at room temperature.

18:- What are proteins?

Ans:- Proteins are body-building food. Proteins help in growth and repair of the injured or damaged parts of the body. Growing children need more of proteins to help rapid growth.

19:- Write all the parts of body that are made of proteins.

Ans:- The body parts that made of proteins are

1-skin, muscles, bones and blood cells are primarily proteins.

2- blood and blood cells are made of proteins which help in the distribution of oxygen, food, antibodies, and enzymes to different parts of the body.

3- Hair on head and nails on fingers are made of pure proteins.

Digestive juices are enzymes and all enzymes are proteins.

20:- What are vitamins?

Ans:- Vitamins are the nutrients which is essential for our good health. They protect our bodies against diseases.

21:- How many types of vitamins? Name them.

Ans:- There are six types of vitamins.

1-Vitamin A

2-Vitamin B

3-Vitamin C

4-Vitsmin D

5-Vitamin E

6-Vitamin K

22:- What is the sources and uses of Vitamin A?

Ans:- Sources-The sources of vitamin A are carrot, papaya, butter, ghee, fish liver oil, corn and green-yellow fruits and vegetables.

Uses-It is useful for healthy skin and bright eyes. It protects us from night blindnrss and dryness of the lining of the mouth.

23:-What is the sources and uses of vitamin B?

Ans:- The sources of vitamin B are yeast, sprouts, wheat-germ, whole grains, brown rice, beans, porridge, bananas, eggs and meat 

Uses- It protects us from diseases like beri-beri, eyesore, and anaemia. It gives us relieves from nerve pain. It protects us from skin disorders and muscle twisting.

24:- What is the sources and uses of vitamin C

Ans:- The sources of vitamin C are orange, lemon, and other citrus fruits, aamla, guava, and green vegetables.

Uses- It protects us from cold, throat and chest infection. It also helps in early repair of injuries.

25:- What is the sources and uses of vitamin D?

Ans:- The sources of vitamin D are milk, fat, fish, liver, egg, cheese, butter, edible oils and sun.

Uses-It makes the bones strong with the help of calcium. It protects us from rickets and bone dosease

26:- Vitamin D is also known as sunshine vitamin. Why?

Ans:- Vitamin D is also known as sunshine vitamin because sunrays react with the oil of skin and produce vitamin D.

27:- What is the sources and uses of vitamon E

Ans:- The sources of vitamin E are wheat-germ, sunflower, olive, almond and walnut.

Usrs- It maintains the freshness of the skin. It also helps in faster healing of damaged tissues.

28:- What is the sources and uses of Vitamin K?

Ans:- The sources of vitamin K are cabbage, spinach, methi and leaves of alfalfa.

Uses:-It prevents us from excessive bleeding. It also helps in clotting of blood.

29:- Who discovered vitamins and when?

Ans:- Casimir funk discovered the vitamins first in 1911.

30:- In how many groups vitamins are divided?

Ans:- Vitamins are divided into two groups

1-fat- soluble vitamins

2-water-soluble vitamins

32:- What is fat-soluble vitamins?

Ans:- The fat-soluble vitamins are A, D, E and K. They stored in the body in fat rich tissues and are used from time to time.

33:- What is water-soluble vitamins?

Ans:- The water-soluble vitamins are B and C. Vitamin B complex has 11 basic units. Thest units are B1, B2, B3, B6, B12, folic acid, pantothenic acid, para-aminobenzoic acid, biotin, choline and inositol. All these vitamins are solluble in water. Water solluble nutritions are not stored in our body. They are replenished everyday along with raw and fresh food.

34:-What are minerals?

Ans:- Minerals are elements in the form of salt. Minerals are required for proper growth, formation of blood cells, healthy bones, and strong teeth for performing important functions of the body.

35:- What is the function of calcium and phosphorus in our body

Ans:- Calcium and phosphorus are required in good quantity for the formation of strong and healthy bones and teeth.

36:- What is the function of sodium in our body?

Ans:- Sodium helps in the flow of blood in our body.

37:- Write short notes on fibres.

Ans:- Fibres are not a nutrient. They help in filling the stomach. Fibers are indigestible but help in digestion. Lack of fibre in our food may result in constipation and hard stools. The fibres are also known as roughage.

38:- Write ten important sources of fibres.

Ans:- The ten important sources of fibres are carrot, radish, turnip, cucumber, cabbage, leafy vegetables, tomato, fruit peel and seed covering of pulses.

39:- What is the daily requirement of iron in humanbody?

Ans:- 25 mili gram

40:- What is the daily requirement of calcium in humanbody?

Ans:- 500 mili gram

41:-What is the daily requirement of phosphorus in humanbody?

Ans:- 1.4 gram

42:- What is the daily requirement of iodine in humanbody?

Ans:- 0.5mili gram

43:- What is the daily requirement of potassium in humanbody?

Ans:- 50 mili gram

44:- What is the daily requirement of sodium in humanbody?

Ans:- 4 gram

45:- What is the common source of iron for human beings

Ans:- Milk, beans, sesame, green leafy vegetables, egg, fish and liver

46:- What is the common source of calcium for human beings?

Ans:- milk, cheese, pulses, soyabean, green leafy vegetables, mineral water, dry fruits.

47:- What is the common source of phosphorus for human beings?
Ans:- milk, nuts, pulses, fruits, fish, meat

48:-What is the common source of iodine for human beings?
Ans:- green vegetables, iodised salt, sea food, marine fish, coconut water

49:- What is the common source of potassium for human beings?
Ans:- milk, green leafy vegetables, whole grains, pulpy fruits

50:- What is the common source of sodium for human beings?

Ans:-common salt, leafy vegetables, milk

51:-What is the common source of magnesium for human beings?

Ans:- green leafy vegetables, cereals, kiwi fruit

52:- What is the common source of zinc for human beings?

Ans:- beans, peanuts, chicken

53:-What is the use of iron in human body?

Ans:-Iron helps in the formation of haemoglobin in red blood cells in human body.

54-Which disease causes due to deficiency of iron in human body ?

Ans:- Anaemia.

55:- What is the use of calcium in human body

Ans: –Calcium makes the bones and teeth strong . Calcium also helps in clotting of blood .

56- Which disease causes due to deficiency of calcium?

Ans :– Deficiency of calcium leads to soft bones .

57:- What is the use of phosphorus in human body ?

Ans:- Phosphorus helps in utilizing proteins in human body. Phosphorus also makes the bones and teeth strong .it also provides energy to our body.

58:-What is the use of iodine in human body? 

Ans:- Iodine helps in normal body growth in human body.

59:- Which disease causes due to deficiency of iodine?

Ans: –The disease causes due to deficiency of iodine is goiter.  In goiter  the thyroid gland swells and becomes larger.

60:-What is the use of potassium in our body?

Ans:-Potassium helps in the formation of new cells and tissues. It is also important for nerve impulses.

61 :– what is the use of sodium in our body?

Ans:- Sodium controls  body liquid, blood flow and nerve impulses .

62:- Which disease cause due to excessive sodium in human body ?

Ans:- Excessive sodium leads to high blood pressure in human body .

63:-What is the use of magnesium in human body ?

Ans:- Magnesium makes the muscles and nerves strong.

64-what is the use of zinc in human body?

Ans:- Zinc  supports digestion of food.  it also works as antacid in human body.

65:-what is the importance of water in our body?

Ans:-The importance of water in our body are

1.It turns the food soft and pulpy .

2.It helps in movement of food through the food canal.

3.It helps in the circulation of blood through the body since 80% of our blood is water.

4.It carries enzymes ,digested food hormones into the blood

5. It keeps our skin moist.

6. It helps muscels in movement.

7. It keeps the body cool and helps us in maintain normal body temperature.

8. It helps in removal of wastes from the body.

66:- How much water should we drink in a day ?

Ans:- We should drink at least 3 to 4 liter of water in a day.

67:- Which disease causes due to loss of water?

Ans:- dehydration

68:- What is balanced diet?

Ans:- A diet that includes adequate number of different components of food required for the healthy  functioning of our body is called a balanced diet

69:- How does a balance diet varies from person to person?

Ans:- balance diet varies according to the age and the nature of the work of a person.

For example- 

§         A child needs more carbohydrates, proteins, vitamins and minerals for energy and growth.

§         A grown up office going person needs moderate amount of carbohydrates, fats , proteins, minerals  and vitamins for the maintenance of the healthy body.

§         A labour performing hard physical work, needs more of carbohydrates to meet the energy  requirements.

70- Why do we need a balance diet?

Ans:- We need a balance diet because balance diet makes us smart and healthy. It also prevents us from many diseases. Balance diet also provides energy to work and play.

71:- When does a person suffer from obesity?

Ans :-A person suffers from obesity when he takes too much carbohydrates and fats in his diet.

72:- What is malnutrition?

Ans:- Malnutrition refers to when a person’s diet does not provide enough nutrients for health.

73:- What are deficiency disease?

 Ans:- The disease causes due to nutritional deficiency in human beings is called deficiency disease.

Ex:- night blindness, beri-beri, rickets

 
74:- Write short notes on protein deficiency diseases.
Ans:- Protein deficiency is caused due to deficiency of protein in diet. it is generally seen in poor family. There are two types of protein deficiency
1-kwashiorkor
2-protein-carbohydrate deficiency 

75:- Which diseases cause due to deficiency of vitamin A?

Ans:- night blindness and dryness in mouth

76:- Which diseases cause due to deficiency of vitamin B1?

Ans:- Beriberi

77:- Which diseases cause due to deficiency of vitamin B12

Ans:- anaemia, skin-rash, weak memory

78:- Which diseases cause due to deficiency of vitamin C

Ans:- scurvy, stiffening of muscles, joint pain.

79:- Which diseases cause due to deficiency of vitamin D

Ans:- Weak bone, tooth decay.

80:- Which diseases cause due to deficiency of vitamin E

Ans:- skin losing glow, wrinkles on face

81:- Which diseases cause due to deficiency of vitamin K

Ans:- Excessive bleeding from injury

82:- Which diseases cause due to deficiency of calcium?

Ans:- The diseases that cause in children due to deficiency of calcium are rickets and deformed teeth

The diseases that cause in adult due to deficiency of calcium are osteoporosis, damage to spine and knees.

83:- Who helps in absorption of calcium in human body?

Ans:- Vitamin D

 

Cleaning of food and separation of substances, chapter-3, class-6

 1:- What is substance?

Ans:-  substance is a matter which has specfic composition or properties.

Ex- sugar, salt etc.

Every pure element is a substance. Every pure compound is a substance.

2:- How many types of substance? Name them.

Ans:- There are three types of substance

1-Pure substance

2- Impure substance

3- Mixture

3:- What is pure substance?

Ans:-A substance that contaons only one element or compound is called pure substance.

For example:- iron, water, sugar, salt etc.

4:- What is impure substance?

Ans:-  Impure substance is made up of two or more than two elements or compounds that are not bounded together chemically.

For example:- sugar in water, sand in water, fruit juice, muddy water etc.

5:- What is mixture?

Ans:-A mixture is the physical combination of two or more substances in which all substances are retained their identities. The components of mixture can be separated by physical mean.

Ex- salt water, mixture of water and sugar

6:- How many types of mixture? Name them.

Ans:- There. are three types of mixture.

1-Solid mixture

2-liquid mixture

3-gaseous mixture

7:-Write two example of solid mixture.

Ans:-soil, food grains

8:- Write six example of liquid mixture.

Ans:- tap water, syrup, a cup of tea, sea water, petroleum

9:- write an example of gaseous mixture.

Ans:- air

10:- How many types of practices can be done by farmers to clean the farm products?

Ans:- There are five practices can be done by farmers to clean the farm products.

1-harvesting

2-threshing

3-winnowing

4-Hand picking

5-sieving

11:- what is harvesting?

Ans:- Harvesting is the process of gathering ripe crops from the field.There are two methods to harvest crops.

1-By hand using sickle

2-By harvester

12:- Write short notes on hand harvesting using sickle.

Ans:- Hand harvesting is done by small farmers. In hand harvesting crops are cut by hand using sickle at the root level. The harvested crop plants are made into stacks and are dried in sun. The dried stacks are then thrashed to separate grains from the stalks and the husk.

13:- What is Threshing?

Ans:- Threshing is the process of loosening the edible part of grain from the chaff to whichit is attached. 

 

14:- Write short notes on threshing.

Ans:- Threshing is a process in which crops are thrashed to get fine grains. Threshing is done by three process.

   1- By beating on hard surface

   2- Trampling by the cattle

   3- By thresher

15:- Write short notes on the trampling by the cattle.

Ans:- In trampling by cattle harvested spikes are sprad on the ground in a circle and bullocks tied to a central axis are made to walk over them in rounds. Cattle's tread upon the spikes and their hoofs help separate the grains, leaving behind a mixture of broken straw, chaff and the grains.

16:- What is winnowing?

 Ans:- Winnowing is farming method   developed by ancient people for     seperating grain from chaff.

17:- Write short notes on winnowing.

  Ans:- Winnowing is used to separate fine grains from straw and chaff with help of blowing wind. In this method farmers stand on a high platform facing the direction of wind and releasing the mixture of straw, chaff and grains form a winnow. Grains beings heavier fall under the winnow. Straw and chaff are being lighter and belown a little away by wind.

18:- What is hand picking?

Ans:- Hand picking is used to remove undesirable components like small pieces, and many other impurities from the grains.

19:- Write two places where hand picking is used.

Ans:- The two places where hand picking is used are 

      1- In separating impurities from grains.        2- In separating unripe fruits from ripe             fruits.

20:- What is sieving?

Ans:- Sieving is a process in which fine particles are separated from bigger particles by using sieve.

21:- Write six places where sieving process is used to separate fine particles from large particles.

Ans:- The six places where sieving process is used are.

  1- Separate large sized grains from finer          impurities.

  2- Separate bran from flour.

  3- Grade nuts of different sizes.

  4- Separate fine sand from coarse sand          or pebbles.

  5- Large pearls from small pearls.

  6- Precious stones of different sizes.

22:- What is floating and sinking method?

Ans:- Floating and sinking method is used to separate the two components from a mixture in which both are solids but one floats and other sinks in water. 

         For example - To remove the dust and straw from the grains.

23:- What is Sediment?

Ans:- Insoluble solid particles which settle down in water is called sediment.

For example:- soil, chalk, sand etc.

24:- What is sedimentation?

Ans:- The process in which insoluble solid settling down in water is called sedimentation.

25:- What is decantation?

Ans:- pouring out liquid without disturbing the sediments is called decantation.

26:- What is solute?

Ans:- The substance that is soluble in any medium is called solute.

For example- sugar, salt, wax etc.

27:- What is solvent?

Ans:- The liquid in which a solute gets dissolved is called a solvent.

For example:- water, milk, kerosene etc.

28:- What is solution?

Ans:- The transparant mixture that is formed when solute dissolve in solvent is called solution

For example:- mixture of water and salt, mixture of water and sugar

29:- What are miscible liquids?

Ans:- Liquids which mix together in all proportions and form a single layer are called miscible liquids.

For example- milk and water , glycerine and water etc.

30:- What are immiscible liquids?

Ans:-  Liquifs which donot mix with each other and form separate layers are called immiscible liquids.

For example- solution of oil and water

31:- What is loading?

Ans:- Loading is a process in which the rate of sedimentation is increased by adding chemical substances like alum.

32:- How does alum work as a loading in muddy water? Explain.

Ana:-  Alum is highly soluble in water. Particles of alum get attached to the clay of muddy water. This increases the weight of mud particles. These heavy particles of alum and dust together settle down fast. And make the water clean fastly.

33:- What is filtration?

Ans:- Filtration is a process that is used to separate an insoluble impurities from a liquid. Strainer, filter paper, wire-mesh and clothes are used as filter equipment for filtration.

34:- Write the name of some solid liquid mixture that is filtered by filtration process.

Ans:-Milk from milkman which include some straw

water from river or pond that have have solid impurities

Tea is filtered for separate tea leaves

35:- What is evaporation?

 Ans:- The process by which a liquid changes into gas is called evaporation.

36:- How can be increase the rate of evaporation?

 Ans:- We can increase the rate of evaporation by.

     1- Increase the temperature

     2- Increase the surface area of liquid

     3- By fast blowing air

37:- What is crystallization?

 Ans:- Formation of crystals of salt on evaporation of water from a solution of salt is called crystallization.

38:- What is crystallization?

 Ans:- The process by which a gas or water vapour changes into liquid is called condensation.

39:- Write three magnetic metal names.

 Ans:- 1- Iron 

           2- Cobalt 

           3- Nickel

40:- What is magnetic separation?

 Ans:- Magnetic separation is the process of separating magnetic materials from magnetic and non magnetic mixture with the help of magnet.

   For example - we can separate mixture                of iron filings and sand by the.                       process of magnetic separation.

41:- What is churing?

  Ans:- Churning is the process that is used to separate cream from milk or curd.

42:- How many types of machines are used in churning?

 Ans:- 1- Wooden ladle

           2- Electrically operated blender 

           3- Churner

43:- How churning helps us in getting butter from curd?

Ans:- Firstly curd is churned with the help of churning machine. Churning machine separates the butter from curd. Butter is lighter than the milky water therefor it start to float above the milky water. By this process we can separate butter from curd.

 

Materials of daily use: clothes, chapter-4, class-6, science

 

 1:- Which is the three basic needs of human?

Ans:-Food, clothes and shelter are the three basic needs of human.

2:- Why do we need clothes?

Ans:- We need clothes because clothes protect our body from roughness of weather.

3:- Why do we wear light shade cotton clothes in summer?

Ans:- We wear light shade cotton clothes in summer because it protect our body from sun.

4:- Why do we wear woollen clothes in winter?

Ans:- We wear woollen clothes in winter because woollen clothes protect our body from cold and wind.

5:- How did people manage when their were no clothes?

Ans:- Early men used hide of animals as clothes to cover their body. They also used big leaves, hide of trees and feathers of birds to cover their body.

6:- What is the meaning of fabric?

Ans:- The meaning of fabric clothes.

7:- What are fibres?

Ans:- Fibres are the fine filament that help in making fabric.

8:- How many types of fibres?

Ans:- There are tow types of fibres.

   1- Natural fibres 

   2- Synthetic fibres

9:- What are natural fibres? Give example.

Ans:- Fibres that are obtained from natural sources like plants and animals are called natural fibres.

      Example- Cotton, Wool, Silk.

10:- What are synthetic fibres?

Ans:- Fibres that are obtained from artificial sources like chemical substances and wood pulps are called synthetic fibres.

      Example- Polyster and Nylon.

11:- How can we prepare a fabric? write process.

Ans:- Fabric is made from fibres. Firstly fibre is spun into yarn. In second stage yarns are adjusted in cross wise pattern to woven into fabric with the help of power looms.

12:- In which climate condition cotton grows well?

Ans:- Cotton grows well in warm climate condition.

13:- In which soil cotton grow well?

Ans:- Cotton grows well in black soil.

14:- Write six name of state where cotton grows?

Ans:- Madhya Pradesh, Maharashtra, Rajsthan, Gujrat, Punjab, and Tamil Nadu.

15:- How can we process cotton? write steps.

Ans:- To process the cotton we follow these three step.

1- PLUCKING- In this step we pluck cotton bolls from cotton plants.

2- GINNING- In this step we separate the cotton fibre from cotton seeds.

3- CARDING- In this step we make cotton fibres fluffy.

16:- What is spinnig?

Ans:- Spinning is a process in which fluffy fibre turns into yarns with the helps of spinning wheels.

17:- What is weaving?

Ans:- Weaving is a process in which fine yarns turns into fabric with the help of power loom. In this process weaving threads are arranged in length wise called wraps and cross wise called weft.

18:- What is knitting?

Ans:- Knitting is a process in which fabric is made by interlocking loops in a single yarn with the help of knitting needles.

19:- Write some garments that are made by knitting process.

Ans:- Vests, Underwear, Sox, Sportdtrack suit.

20:- Write seven uses of cotton.

Ans:- The seven uses of cotton is.

 1- It is used to make various kinds of fabrics like sheets, curtains, carpets and towels.

 2- It is widely used in surgical cotton, surgical bandages and wiping clothes because it absorbs water fastly.

 3- It is used to make wicks for oil - lamp.

 4- It is used as filler for stuffing pillows.         and quilts.

 5- It is used to make fine quality paper.

 6- It is used in making rayon.

 7- It is used to make reel thread for                  stitching garments.

21:- Write the name of states where juit is cultivated?

Ans:- West bengal, Bihar, Odisha, Assam, and Tripura.

22:- In which climate condition juit grows well?

Ans:- Juit grows well where their alot of rain.

23:- In which soil juit well grows?

Ans:- Juit well grows in flooded soil.

24:- What is the time period of harvesting juit in India?

Ans:- Juit is sown towards march and harvesting by September.

25:- Write four uses of juit.

Ans:- The four uses of juit are.

1- It is used in making strings.

2- It is used in making hand bag and gunny- bag.

3- It is used in making carpets and rugs.

4- It is used in making coarse clothes.

26:- What is hemp?

Ans:- Hemp is a type of fibre. It is tougher and little bright than juit. In India it is also called sunn.

27:- Write three uses of hemp.

Ans:- The three uses of hemp are.

 1- It is used in making handbags and carpet.

 2- It is used in making better quality gunny - bags, nets and paper.

3- It is used in making ropes for tents and drawing water from wells.

28:- What is lenin?

Ans:- Lenin is a types of fibre that comes from flax plant.

29:- Write some uses of linen.

 Ans:- Linen is used in making curten, table clothes and lungi.

30:- What is coir?

Ans:- Coir is a type of fibre that we get from wark of coconut fruits.

31:- Write three uses of coir fibre.

Ans:- The three uses of coir fibre are.

 1- It is used in making foot mats.

 2- It is used  in making carpets.

 3- It is used in making ropes and rungs.

32:- What is kapok?

Ans:- Kapok is a type of fibre that is useful in making silk cotton. It is also known as simul.

33:- Write two uses of kapok.

Ans:- The two uses of kapok are.

 1- It is used in making silk cotton.

 2- It is used as filler in cushion and pillows.

34:- Write four advantage of natural fibre.

Ans:- The four advantage of natural fibre are.

 1- They are resistant to fire to some.                extent.

 2- Natural fibres are easily affordable.

 3- These fibres absorb sweat and water.          easily

 4- Natural fibres are safe for human skin.       and are biodegradable.

35:- Write four disadvantage of natural fibre.

Ans:- The four disadvantage of natural fibre.

 1- The strength of natural fibres is very as. compared to synthetic fibres.

 2- Natural fibres are heavy in weight.

 3- Natural fibres can easily be damaged by moths and other insects.

 4:- These fibres are not wrinkle- free.

 

Kinds of materials, chapter-5, class-6, science

 

 1:-What are natural objects?

Ans:- Object that are made by nature is Called natural is called natural object.

      Ex:- Sky, Sun, Moon, Air, Water etc.

2:-What are man made object?

Ans:- Objects that are made by man are called man made object.

     Ex:- Fan, Table, Pen etc.

3:- What is material?

Ans:- The substance which is used to make an object is called substances.

        Ex:- Wood, Soil, Ghee etc.

4:- What is matter?

Ans:- Anything which has volume and mass is called matter.

       Ex:- Book, Bed etc.

5:- What is volume?

Ans:- The space occupied by an object is called its volume.

6:- How many types of matter.

Ans:- There are three types of matter.

  1- Solid

  2- Liquid

  3- Gas

7:- What is solid?

Ans:- Matter which have fixed shape and volume is called solid.

         Ex:- Ice, Bricks, Wood etc.

8:- What is liquid?

Ans:- Matter which have fixed volume but does not fixed shape is called liquid.

         Ex:- Water, Milk, Oil etc.

9:- What is gas?

Ans:- Matter which does not have fixed shape and volume is called gas.

          Ex:- Air, Water vapour etc.

10:- What is inter molercular force?

Ans:- The force of attraction that is found between two molecules of same matter is called inter molecular force.

* The inter molecular force is greatest in solid. The inter molecular force of liquid is less than solid but greater than gas.The inter molecular force of gas is very less than both solid and liquid.

11:- What is inter molecular space?

Ans:- The space that is found between two molecules of the same matter is called inter molecular space.

* The molecular space is greatest in gas . The molecular space in liquid is less than gas greater than solid. The molecular space in solid is very less than both liquid and gas.

12:- Why does a solid ritens their fixed shape and fixed volume?

Ans:- Solid ritens fixed shape and fixed volume because it has very strong molecular force. Molecular force keeps the molecules of solid tightly packed to each other.

13:-Why does a gas riten their unfixed shape and volume?

Ans:- Gas retains unfixed shape and volume because it has very negligible molecular force. 

14:- What is metal? 

Ans:- Those opaque lustrous elements that are good conductor of heat and electricity is called metal.

       Ex:- Iron, Copper etc.

15:- Write six properties of metal.

Ans:- The six propertied of metal are.

 1- Metals have a special sign called lustrous.

2- Metals are flexible. It can be easily bent.

3- Metals are good conductor of heat.

4- Metals are good conductor of electricity.

5- Metals are mallable. They can be beaten into thin sheets.

6- Metals are ductile. They can be drawn into wire.

16:- Write five uses of metals.

Ans:- The five uses of metals are.

1- Metals are used to make kitchen utensils.

2- Metals are used to make electrical cables.

3- Metals are used to make machines.

4- Metals are used to make scientific instrument.

5- Metals are used in make jwellry.

17:-  Write eight properties of glass.

Ans:- The eight properties of glass.

1- Glass is shiny

2- Glass is smooth

3- Glass is hard

4- Glass is non- flexible

5- Glass is brittle

6- Glass is non- conductor of heat and electricity

7- Glass is transpatent

8- Heated glass can be moulded to any shape.

18:- Write five uses of glass.

Ans:- The five uses of glass are.

1- Glass is used  to make science upparatus.

2- Glass is used to make strong bottles.

3- Glass is used to make elerctric bulbs.

4- Glass is used to make doors and windows.

5- Glass is used to make mirrors.

19:- Write six properties of plastic.

Ans:- The six properties of plastic are.

1- Plastic is flexible.

2- Plastic floats on water.

3- Plastic melts on heating easily.

4- Plastic can be moulded to any shape.

5- Plastic catches fire on flame easily.

6- Plastic may be transparent or translucent.

20:- Write four uses of plastic.

Ans:- The four uses of plastic are.

1- It is used for making items of kitchen.

2- It is used for making electric switches.

3- It is used for making house hold items like table, chair etc.

4- It is used for making car bodies.

21:- Write four properties of water.

Ans:- The four properties of water are.

1- Water has no shape of its own.

2- Water is colourless.

3- Water is odourless.

4- Water aquires the shape of the vessels in which it is poured.

22:- Write two materials that are rough in natute.

Ans:- Bark of tree, sand paper.

23:- Write two materials that are smooth in nature.

Ans:- Sheets of glass, Floor tiles.

24:- Write two metals that are more lustrous.

Ans:- Gold, Silver.

25:- What are hard materials? Write two example.

Ans:- Materials which can not be easily pressed or compressed are called hard materials.

        Ex:- Steel, Iron, Rock etc

26:- What are soft materials?

Ans:- Materials which can easily pressed or compressed are called soft materials.

    Ex:- Rubber, Wax etc.

27:- What is transparent materials?

Ans:- Those materials by which light can pass easily and completely are called transparent maerials.

      Ex:- Glass, Acrylic, Air etc.

28:- What are translucent materials?

Ans:- Those materials by which light can pass partially and we can not see clearly through them are called translucent materials.

     Ex:- Frosted glass, Milky water.

29:- What are opaque materials? Write example.

Ans:- Those materials that do not allow the light to pass through them are called opaque materials.

        Ex:- Wood, Metal sheet, Rock etc.

30:- Why does wood float in water?

Ans:- Wood floats in water because the density of wood is less than the density of water.

31:- Why does an iron nail sink in water?

Ans:- Iron nail sinks in water because the density of iron nails is greater than the water.

32:- Write two materials that are soluble in water.

Ans:- Sugar and Salt.

33:- Write two materials that are insoluble in water.

Ans:- Sand and Wax.

34:- Write a material that is soluble in kerosene.

Ans:- Wax

35:- Write four liquids that are miscible in water.

Ans:- Glycerine, Vinegar, Alcohol and honey.

36:- Write two liquids that are immiscible in water.

Ans:- Mustard oil, Kerosene.

37:- Write two liquids that are miscible in mustard oil.

Ans:- Groundnut oil, Coconut oil.

38:- Write a liquids that is miscible in kerosene.

Ans:- Petrol

39:- Write a gas that is not soluble in water.

Ans:- Nitrogen

40:- Write two gases that is partly miscible in water.

Ans:- Carbon- dioxide, oxygen.

41:- What is conductor? Write example.

Ans:- The material that allows heat and electricity to flow through them is called conductor.

     Ex:- Iron, Copper, Silver, etc.

42:- What is insulator? Write example.

Ans:- The material that does not allows heat and electricity to pass through them is called insulator.

       Ex:- Rubber, Wood, Cardboard etc.

 

Changes around us, chapter-6, class-6, science

 

 

1:- How many types of change?

Ans:- There are two types of change.

 1- Reversible change

 2- Irreversible change

2:- What is reversible change?

Ans:- Reversible change is the change that can be reversed. In reversible change no new substance is formed. It is also known as physical change.

     Ex:- Melting of ice, Tearing of paper,                     Freezing of water etc.

3:- What is irreversible change?

Ans:- Irreversible change is the change that can not be reversed. In irreversible change new substance is formed. It is also known as chemical change.

  Ex:- Curding of milk, Burning of paper,                  Cooking rice etc.

4:- What is melting?

Ans:- Melting is the process by which a substance changes from the solid phase to the liquid phase.

      Ex:- Ice melts to become water that is.                liquid.

5:- What is evaporation?

Ans:- Evaporation is the process by which a substance changes from liquid phase to the gasious phase.

  Ex:- Water boils to become water vapour.            that is example of evaporation.

6:- What is condensation?

Ans:- Condensation is the process by which a substance changes from gasious phase to the liquid phase.

      Ex:- Water vapour cools to become.                     water.

7:- What is freezing?

Ans:- Freezing is the process by which a substance changes from liquid phase to the solid phase.

     Ex:- When water cools down below the.               0 degree celsius it becomes ice.

8:- What are natural changes? Give example.

Ans:- The changes that are taking place in nature are called natural changes.

  Ex:- Cloud changes into rain when it.                   cools.

         Blooming of flowers.

9:- What are man made changes?

Ans:- The changes that are made by man are called man made changes.

  Ex:- Coocking of food.

         Construction of house.

10:- Write nine example of reversible.                  change.

  1- Change in the state of water on                    heating or cooling.

  2- Stretching of a rubber band or a spring.

  3-Making a coil of a metallic wire.

  4- Putting on a light, a fan or heater.

  5- Heating an iron nail to red-hot stage.

  6- Melting of wax.

  7- Preparing clay models from wet clay.

  8- Making chapaati from dough.

  9- Preparing solutions by dissolving                salt / sugar in water.

11:- Which types of change is expansion and contraction of metal?

Ans:- Expansion and contraction of metal is a physical change.

12:- What happens when solids get heated?

Ans:- When solids get heated, they expend.

13:- What happens when solids get cooled?

Ans:- When solids get cooled, they contract.

14:- What happens when liquid get heated?

Ans:- When liquid get heated, they expend.

15:- What happens when liquid get cooled?

Ans:- When liquid get cooled, they cotract.

16:- What happens when gas get heated?

Ans:- When gas get heated, they expend.

17:- What happens when gas get cooled?

Ans:- When gas get cooled, they cotract.

18:- Why does buildings have expansion gaps at the joint between two beams?

Ans:- The building have expansion gaps between two beams because without these gaps the building may develop cracks due to pressure from expansion and contraction generated by heating and cooling of environment.

19:- Why do railway tracks have gaps?

Ans:- Two railway tracks have gaps between them because during summer the rails expand and during winter they contract. Thus the gap saves the rails from getting curved.

20:- Why is mercury used in thermometer to measure the temperature of a body?

Ans:- Mercury is a lustrous non-sticky liquid metal seen clearly inside a glass tube. It has a special characteristic of expanding or contracting uniformly with every degree rise or lowering in temperature. For these characteristic mercury is used in thermometers to measure the temperature of a body.

21:- How does hot air balloon lift up into the air? Write process.

Ans:- Hot air balloons which rise into the sky have a small pot with burning material in a pot under the canopy or the balloon. On heating, air in the balloon expands and becomes light in weight, lifting the balloon up into the air.

22:- How does the colour of copper sulphate a reversible change? Explain.

Ans:- Take a deep blue crystal of copper sulphate. Keep it on a pan and warm it over a flame. As the crystal gets heated, water from the crystal evaporates and it looses its blue colour and changes to white powdery mass and let it cool. It regains its blue colour. This proves that the colour of copper sulphate is reversible change.

23:- How does the colour of potassium dichromate a reversible change? Explain.

Ans:- Take a deep pink crystal of potassium dichromate. Keep it on a pan and warm it over a flame. As the crystal gets heated it changes its colour to blue. Add a few drops of water to the blue potassium dichromate. It regains its deep pink colour.

24:- What is solubility?

Ans:- Solubility is the ablity of a substance to get dissolved in a liquid.

25:- Write four factor that affect solubility.

Ans:- The four factor that affect solubility are.

1- The solubility of a substance increases when the solution is stirred.

2- The solubility of a substance is different

with different solutes.

3- Large size crystals take more time to dissolve than powdered solute.

4- Solubility is affected by the temperature of the solvent when temperature will increase the solubility will also increase and when temperature will decrease the solubility will also decrease.

26:- What are saturated solution?

Ans:- A solution in which no more solute can be dissolved in the solvent is called saturated solution.

27:- What is the effect of heating and cooling on saturated solution?

Ans:- EFFECT OF HEATING: Take the saturated solution of salt prepared in water at room temperature. Warm it slowly on low heat. Obserb that the salt which had settled at the bottom of the beaker gets dissolved. Add more salt to it till no more salt goes into the solution. This shows that solubility of a solute increases with the rise in temperature.

EFFECT OF COOLING: Withdraw the hot saturated solution from the flame and let it

cool. You will observe that as the temperature of the solution comes down more and more salt gets settled at the bottom of the beaker. This shows that solubility of a solute decrease with the lowering of temperature.

 

 28:- What is irreversible change?

Ans:- 

Chapter- 7

Flowering Plants - forms and functions

1- What are flowering plants?

Ans:- Plants that bear flowers are called flowering plants.

Ex:- sunflower, rose, potato, paddy, mango etc.

2- How many types of flowering plants on the basis of size?

Ans:- There are three types of flowering plants on the basis of size.

1- herbs

2- shrubs

3- trees