NCERT 6th Class (CBSE) Science: Air Around Us

Question: What is the oxygen cycle?

Answer: The natural cycle of consumption of oxygen by respiration and burning and its release by photosynthesis is called the oxygen cycle.

Question: list the uses of air.

Answer: Besides breathing, air is useful to us in many other ways.

1. The wind makes windmills rotate. The windmills are used to draw water from tube wells and run flour mills. It is now being widely used to generate electricity.
2. Aeroplanes, helicopters, balloons, parachutes and yachts work because of air.
3. Birds, insects and bats are able to fly because of the presence of air.
4. Air helps in the dispersal of seeds.
5. Air helps in pollination of several flowers.
6. Air plays an important role in the water cycle.

Question: How does the atmosphere help to maintain the right temperature on the earth?

Answer: The atmosphere helps to maintain the right temperature on the earth. The heat and light of the sun fall on the earth’s atmosphere. Some of it is absorbed by the atmosphere, while the rest is reflected back. This prevents the earth from becoming very hot during the day. At night, the trapped heat in the atmosphere prevents the earth from cooling down too much. The atmosphere, thus, acts like a blanket around the earth and helps to keep the earth’s surface at the right temperature for life to exist.