Page 84 - Active Science 5 Ebook and Activity

D. State whether the following statements are true or false.

1. Troposphere is the lowest layer of atmosphere. _____
2. Water is made up of two atoms of hydrogen and one atom of oxygen. _____

3. Air exerts pressure in all directions. _____
4. Nitrogen can convert to oxygen in the process of photosynthesis. _____

5. The process of converting a liquid to vapour is called distillation. _____

E. Name these:
1. Two gases present in the air ______________________

2. Two non-polluting fuels ______________________
3. Two kinds of impurities in water ______________________

4. Two properties of water ______________________
5. Two methods of removing soluble substances from water ______________________

F. Short Answer Questions.
1. What is air made of?
2. Why is air important for living things?

3. Write the definition of atmospheric pressure?
4. What is filtration?

5. Write the benefit of boiling water.
6. What does humidity indicate?

G. Long Answer Questions.

1. What are the different components of air?
2. Write any five properties of air.
3. Explain importance of oxygen for human survival.

4. Define sedimentation.
5. Define decantation.

6. How can water be purified with the help of distillation?

Think Hard

Give reason why:
• Bubbles come out when a lump of soil is put in water.

• If a burning candle is covered by a glass, it soon goes out.

84 Active Science-5