Class 6 Science Chapter 4 Sorting Materials Into Groups Extra Questions

CBSE Class 6 Science Chapter 4 Sorting Materials Into Groups Extra Questions and Answers is available here. Students can learn and download the PDF of these questions for free. These extra questions and answers are prepared by our expert teachers as per the latest NCERT textbook and guidelines. Learning these extra questions will help you to score excellent marks in the final exams.

Sorting Materials Into Groups Class 6 Science Extra Questions and Answers

Very Short Answer Questions

Very Short Answer Type Questions -II

1. Why do we need to group materials? Give one reason.
Answer: We often group materials for our convenience. It helps to describe their properties.

2. Suggest two bases on which we can group objects.
(i) Material used in making the object, e.g. wood or metal/plastic.
(ii) Material of the object is soft or hard, or substance is soluble or insoluble in water.

3. Is a substance which can be compressed soft or hard?
Answer: Soft.

4. Select a lustrous material out of the following substances:
Answer: Aluminium.

5. Which material is generally used for making pens? Wood, aluminium, plastic, cotton 
Answer: Plastic or metal.

6. Is oil soluble in water?
Answer: Oil does not dissolve in water so it is insoluble in water but floats on the surface of water.

7. Name two objects which are made from opaque materials.
Answer: Wooden doors, blackboard/steel plate.

8. What is common between salt and sand?
Answer: Both have mass and are in solid state.

9. List three liquids which are transparent.
Answer: Water, alcohol and Acetone/Benzene.

10. Write two substances which are made from leather.
Answer: Belt and shoes.

11. Name some substances which are made from plastics.
Answer: Toys, plates, cups, buckets, baskets.

12. Which is more hard, sponge or iron?
Answer: Iron is harder than sponge.

13. Write two gases which are soluble in water.
Answer: Oxygen, Carbon dioxide.

14. Name two gases which are insoluble in water.
Answer: Hydrogen and Nitrogen.

15. Name a non-metal that has lustre.
Answer: Iodine.

16. Take a small cotton ball and place it in a tumbler/bowl filled with water. Observe it for atleast 10 minutes. Will it float or sink in water and why?
Answer: Cotton ball initially floats and then sinks as it absorbs water.

17. Which property of gases helps us in detecting leakage of cooking gas?
Answer: The property of diffusion.

18. Name the two gases used by aquatic plants and animals, that are soluble in water.
Answer: Oxygen and carbon dioxide are used by animals and aquatic plants.

19. What do you understand by the word ‘classification’?
Answer: Classification means grouping the things on the basis of their similarities and dissimilarities.

20. Give an example to explain that one object can be made from different materials.
Answer: A plate can be made from steel, glass or plastic.

21. Give one example to explain that different materials are used to make one object.
Answer: A bag is made of cloth, plastic and metal.

22. What is a combustible material?
Answer: A material which burns on heating at a particular temperature is a combustible material.

Short Type Questions & Answers

1: Name five items which can be made of plastic.
Answer: Five items that can be made of plastic are plate, phone, pencil box, pen and chair.

2: Classify these objects as eatables or non eatables.
Sugar, apple, ball, pen, pot, grapes, chocolates

Answer: Eatables- sugar, apple, grapes and chocolates.
Non eatables-ball, pen and pot

3: Which of these objects are made of wood and which of them are made of paper?
Table, chair, newspaper, calendar, bullock cart, notebook

Answer: Objects made of wood- table, chair and bullock cart. Objects made of paper- newspaper, calendar and notebook.

4: Which of the following are shiny objects:
Wood, copper wire, paper, chalk, aluminium sheet, steel spoon

Answer: Copper wire, aluminium sheet and steel spoon are shiny objects.

5: What is the difference between soft and hard material?
Answer: Soft materials are those which can be compressed or scratched easily.

6: Why some materials lose their shine and appear dull?

Answer: Some materials often lose their shine and appear dull because of the action of air and moisture on them.

7: What types of substances are soluble in water? Give example.

Answer: Substances that completely disappear or dissolve in water are soluble in water. For example-salt, sugar etc.

8: What type of substances is called translucent?

Answer: The materials through which objects can be seen but not clearly are known as
translucent. For example-oily patch on paper.

9: Classify the following on the basis of float or sink in water:
Leaf, key, apple, stone, paper

Answer: Float in water: leaf, paper
Sink in water: key, apple and stone.

10: Classify the following as transparent or translucent or opaque material:
Cardboard, glass, water, oily paper, wood, stone, metal

Answer: Transparent –glass, water.
Translucent-oily paper
Opaque-cardboard, wood, stone, metal.

11: What do you mean by the term ‘transparent’?

Answer: Those substances or material, through which things can be seen are called transparent. For example-water, glass etc.

12: Find the odd one out:
a. Iron, wood, nail, cotton.
b. Sugar, salt, sand, milk
c. Copper, wood, aluminium, gold.
d. Table, chair, coin, bed

Answer: Cotton, sand, wood, coin.

13: What is the difference between transparent and translucent?

Answer: Those substances or material, through which things can be seen are called transparent. For example-water, glass etc.
The materials through which objects can be seen but not clearly are known as translucent. For example-oily patch on paper, butter paper.

14: Why do we need to group materials?

Answer: Dividing materials into groups makes it easy to study their properties. It also helps to observe any pattern in these properties. For example: by placing similar types of objects together, we can locate them easily

15. What are the similarities between iron, copper and aluminium?

(a) They all have lustre,
(b) They are all metals,
(c) They are hard.

16. Mention some materials which are made up of paper.
Answer: Books, notebooks, newspapers, toys, calendars, etc.

17. Why is water important for our body?
Answer: Water can dissolve a large number of substances, so it is needed by the body. It is also major part of our body cells.

18. What is the basis for sorting materials?
Answer: Materials are grouped on the basis of similarities or dissimilarities in their properties.

19. What is the reason for grouping materials?
Answer: Materials are grouped for our convenience to study their properties and also observe any patterns in these properties.

20. Metals have lustre (shine). Give reason why some metal articles become dull and lose their shine.
Answer: Metals when exposed to air react with moisture and gases present in it, thereby forming a dull layer of some other compound on it.

21. Kerosene, coconut oil, mustard oil do not dissolve in water, even on shaking. They separate after sometime forming two different layers. Explain why.

Answer: The molecules of water do not intermingle (mix) with the molecules of oil. The space between the molecules of water is not taken by oil, so they are immiscible in water.

22. Metals generally occur in solid state and are hard. Name a metal that exists in liquid state and a metal that is soft and can be cut with knife.

Answer: Mercury is a metal that exists in liquid state. Sodium and Potassium are soft metals and can be cut with knife.

25. Name the naturally occurring hardest substance known.
Answer: Diamond, it is made up of carbon (non-metal).

24. Why is water called a universal solvent?
Answer: Water dissolves a large number of substances in it. So, it is called universal solvent.

25. Why do we classify materials into different groups?

Answer: Materials are classified into different groups for the following reasons:
i. For the convenience of identifying and locating the different materials.
ii. To study their properties and identify common patterns among them.

26. How is density of an object related to its floating or sinking?

Answer: An object will only float if its density is less than that of the surrounding liquid. It will sink if its density is greater than that of the surrounding liquid.

27. Give one example of each of a combustible liquid, gas and solid.

Answer: Petrol is a combustible liquid, CNG is a combustible gas and paper is a combustible solid

28. Why do you think oxygen dissolved in water is important for the survival of aquatic animals and plants?

Answer: Dissolved oxygen is available for animals and plants for respiration and survival.

29. A solid is put in a bucket of water. It floats just below the surface of the water. What do you think is the density of the object with relation to the density of water?

Answer: The density of the solid and water is same because solid neither sinks nor floats on water.

30. Water and starch are mixed in a container. What kind of solution will we get?

Answer: When little amount of starch is added it will dissolve in water. But as the amount of starch increases, the solution starts thickening and forms a suspension.

Long Answer Type Questions

1. ‘Grouping of objects helps the shopkeeper.’ Justify the statement.

Answer: Proper grouping of objects helps shopkeeper in the following ways:
(i) He can locate the required object easily and quickly.
(ii) He can easily come to know what stocks are going to finish and he should purchase them for his customers.

2. Describe an experiment to prove that water is transparent.

Answer: Take a beaker half-filled with clean water. Put a coin in beaker of water.
Place the beaker undisturbed for a few minutes where enough light is present. Now, observe the coin immersed in water from the top of the beaker. Are you able to see the coin? You can clearly see the coin immersed in water. This proves that water is a transparent liquid.

3. Write an experiment to show that our palm is translucent.

Answer: Cover the glass of a torch with your palm at a dark place. Switch on the torch and observe from the other side of palm. We see that the light of torch passes through palm but not clearly. This experiment shows that our palm becomes translucent when a strong beam of light passes through it.

4. Write any four properties of materials.
(a) Appearance
(b) Hardness
(c) Solubility
(d) Float or sink in water
(e) Transparency

5. Why is a tumbler not made with a piece of cloth?

Answer: We use tumblers made of glass, plastic and metal to keep a liquid. These substances can hold a liquid.
A tumbler made of cloth cannot hold a liquid because:
(i) Cloth piece is not hard enough to hold liquids and
(ii) Cloth piece has very minute pores through which the liquid oozes out.

6. Define soluble, insoluble substances and solubility.

Answer: The substances which dissolves in water are called soluble substances. For example: Salt, sugar, milk, etc. The substances which do not dissolve in water are called insoluble substances. For example: Chalk powder, sand, stone, etc. The property of substance due to which it dissolves in water is called solubility.

7. Chalk, iron nail, wood, aluminium, candle, cotton usually look different from
each other. Give some properties by which we can prove that these materials are

Answer: The given materials can be differentiated on the basis of lustre, hardness, softness, roughness or smoothness.

Iron nail

8. Differentiate among opaque, translucent and transparent materials, giving one example of each.


Opaque materialsTranslucent
Transparent materials
Objects cannot be seen
through them
Objects can be
partially seen through
Objects can be seen
clearly through them
Example: CardboardExample: Oiled paperExample: Hand lens

9. How can materials be grouped together? In what ways do we classify materials?

Answer: Different materials have different properties. Materials with similar properties can be grouped together.
Different types of materials can be grouped based on any of the following properties:

  • Appearance
  • Solubility
  • Transparency
  • Conductivity
  • Combustibility—Easily burn or not.
  • Attraction towards magnet.

10: According to the property of hardness, how would you differentiate whether the object is soft or hard? Justify your answer.

Answer: When you press different materials with your hands, some of them may be hard to compress while others can be easily compressed. Take a metal key and try to scratch with it, the surface of a piece of wood, aluminium, a piece of stone, a nail, candle, chalk, any other material or object. You can easily scratch some materials, while some cannot be scratched so easily. Materials which can be compressed or scratched easily are called “soft” while some other materials which are difficult to compress are called “hard”. For example, cotton or sponge is soft while iron is hard.

11: How does appearance of objects help us to make sort out of different materials? Show with an activity.

Answer: Collect small pieces of different materials – paper, cardboard, wood, copper wire, aluminium sheet, chalk. Separate the shiny materials into a group. Now, cuts each material into two pieces and look at the freshly cut surface. Some of these materials are appear shiny. Include these objects also in the group of shiny materials. Instead of cutting, you can rub the surface of material with sand paper to see if it has lustre. Materials that have such lustre are usually metals. Iron, copper, aluminium and gold are examples of metals. Therefore, we can differentiate the materials, according to the lustre.