Air and what it is made of · वायु और उसके घटक
A free Chemistry lesson for Class 4 children.
Air is all around us. We cannot see it, but we can feel it when the wind blows.
Air is a mixture of many gases.
Most of the air is nitrogen. About 78 parts out of 100 are nitrogen.
About 21 parts out of 100 are oxygen. We need oxygen to breathe.
Air also has a little carbon dioxide, water vapour and dust.
Green plants use carbon dioxide to make food. They give out oxygen.
Things need oxygen to burn. A candle goes out when it gets no fresh air.
Air has weight and it takes up space.