Q1. Fill in the blanks:
i. We cannot see air but we can it.
Ans. feel
ii. The blanket of air surrounding the earth is known as .
Ans. atmosphere
iii. is essential for supporting life on the earth.
Ans. Oxygen
iv. Air occupies .
Ans. space
v. Winnowing is more effective in air.
Ans. moving
Q2. True/False:
i. Air is found everywhere.
Ans. True
ii. Soil does not contain air.
Ans. False
iii. The moving air makes it possible for you to fly your kite.
Ans. True
iv. Carbon dioxide supports burning of a candle.
Ans. False
v. Birds, bats and insects can fly due to the presence of air.
Ans. True
Q5. Which gas is important for burning to occur?
Ans. Oxygen is essential for burning
Q6. What percentage of air is oxygen?
Ans. About 21% of air is oxygen.
Q7. What is the name of the gas we breathe in?
Ans. Oxygen
Q8. What is the name of the gas we breathe out?
Ans. Carbon dioxide
Q9. Which device is used to harness wind energy to generate electricity?
Ans. Wind mill
Q10. What makes firki to rotate?
Ans. Moving air makes firki to rotate.
Q11. What is wind?
Ans. Air in motion is called wind.
Q12. What may even uproot trees and blow off the rooftops?
Ans. Strong winds, cyclones, and storms can uproot trees and blow off rooftops.
Q13. What are those tiny shining particles in the beam of sunlight?
Ans. Those tiny shining particles are the dust particles present in the air.
Q14. What do you understand by atmosphere?
Ans. The atmosphere is the layer of air that surrounds the Earth.
Q15. From where does oxygen come in the air?
Ans. Plants release oxygen into the air through the process of photosynthesis.
Q16. Which component of air used by green plants to make their food?
Ans. Green plants use carbon dioxide from the air to make their food through photosynthesis.
Q17. Why air is called a mixture of gases?
Ans. Air is a mixture of gases because it contains various gases like nitrogen, oxygen, carbon dioxide, and water vapor, each retaining its properties.
Q18. Why pages of an open book begin fluttering when the fan is switched on?
Ans. Pages of an open book flutter when the fan is switched on due to moving air (wind).
Q20. How do we feel the presence of air?
Ans. We cannot see the air around us but we can feel its presence when the leaves of the trees rustle or the clothes hanging on a clothes-line sway.
1. What is air and why is it important? | ![]() |
2. How is air polluted and what are the effects of air pollution? | ![]() |
3. What is the composition of air and in what proportions? | ![]() |
4. How does air pressure change with altitude? | ![]() |
5. What are the different layers of the Earth's atmosphere? | ![]() |