Usha took a lump of dry soil in a glass and added water to it till it was completely immersed. She observed bubbles coming out. The bubbles contain

Which of the following components of air is present in the largest amount in the atmosphere?

The components of air which are harmful to living beings are

State whether the following statements are true or false. If false, correct them.

(a) Plants consume oxygen for respiration.

(b) Plants produce oxygen during the process of making their own food.

(c) Air helps in the movements of sailing yachts and glider but plays no role in the flight of birds and aeroplanes.

(d) Air does not occupy any space.

In a number of musical instruments, air plays an important role. Can you name some such instruments?