This PSEB 6th Class Science Notes Chapter 15 Air Around Us will help you in revision during exams.
PSEB 6th Class Science Notes Chapter 15 Air Around Us
→ All living things require air to live.
→ Air is present everywhere around us however we cannot see the air.
→ Our earth is surrounded by a thin layer of air that extends upto many kilometres above the surface of the earth. This is known as the atmosphere.
→ Air is made up of water vapours, Oxygen, Nitrogen, Carbon dioxide, dust, and smoke.
→ Nitrogen and Oxygen are the main constituents of air and are present in large quantities.
→ In the air, nitrogen is 78% and oxygen is only 21%.
→ Oxygen is required for burning.
→ Carbon dioxide is a greenhouse gas.
→ The balance of Oxygen and Carbon dioxide in the atmosphere is maintained by the presence of living organisms (man, animals) and plants.
→ Carbon dioxide is used by plants for producing food by photosynthesis. They release oxygen.
→ Oxygen is consumed by animals and humans for respiration. They produce carbon dioxide.
→ Carbon dioxide is used as a fire extinguisher because carbon dioxide does not support g burning.
→ Air can be compressed and it also exerts pressure.
→ Moving air is called wind.
→ Moving air has the power to rotate a windmill which produces electricity.
→ Windmills are very useful as they produce electricity.
→ Air helps in the dispersal of seeds, pollens, and movement of sailing boats, yachts, gliders, aeroplanes, etc.
→ Dispersal of pollens is known as pollination.
→ Ozone present in the upper layer of the atmosphere protects us from the UV rays of the sun.
→ Air: It is a mixture of many gases like nitrogen, oxygen, carbon dioxide, water vapours, etc.
→ Wind: The moving air is wind.
→ Windmill: A device that is being rotated by air and is used for producing electricity.
→ Atmosphere: The thin blanket of air surrounding the earth constitutes the atmosphere.