NCERT Solutions for Class 6 Science Chapter 15 Air Around Us

Q.1 What is the composition of air?

Answer :

Air contains nitrogen, oxygen, carbon dioxide, water vapour, dust particle and other gases

Q.2 Which gas in the atmosphere is essential for respiration?

Answer :

Oxygen

Q.3 How will you prove that air supports burning?

Answer :

Fix two small candle of the same length on the table. Light both the candles. Cover one of the candles with an inverted glass tumbler. Observe both the candles carefully.
We must have observed that the candle covered with glass tumbler got extinguished after some time, whereas the other candle continued burning. Then proved air support burning Because the glass which did not have oxygen, the candle was extinguished.

Q.4 How will you show that air is dissolved in water?

Answer :

Take some water in a glass vessel or beaker. Heat it slowly on a tripod stand. Before the water begins to boil, look carefully at the inner surface of the vessel. You will see tiny bubbles on the inside. On heating, air dissolved in water escapes in the form of these bubbles.

Q.5 Why does a lump of cotton wool shrink in water?

Answer :

A lump of cotton wool shrinks in water because the air inside wool cotton is driven out by water. The layers stick together and hence lump shrinks.

Q.6 The layer of air around the earth is known as ___________.

Answer :

Atmosphere

Q.7 The component of air used by green plants to make their food, is ___________.

Answer :

Carbon dioxide

Q.8 List five activities that are possible due to the presence of air.

Answer :

Respiration, photosynthesis, burning of any substance, flying of bird, formation of cloud and flying of kite

Q.9 How do plants and animals help each other in the exchange of gases in the atmosphere?

Answer :

In photosynthesis, plants take carbon dioxide and give out oxygen. The animals breath in oxygen in respiration and carbon dioxide is given out which is again used by plants for photosynthesis, that is, preparation of food by plants. This is how plants and animals help each other in the exchange of gases in the atmosphere.