Air is a mixture of gases that surrounds our planet earth. It is essential for the survival of all living things. We breathe in oxygen and breathe out carbon dioxide; plants in turn use carbon dioxide for photosynthesis and release oxygen into the atmosphere.
1. Composition of Air
| Gas | Percentage in air |
|---|---|
| Nitrogen | 78.09% |
| Oxygen | 20.95% |
| Argon | 0.93% |
| Carbon dioxide | 0.04% |
| Other gases | Small amount |
- Since men have been cutting down trees for their needs, the amount of carbon dioxide in the atmosphere is increasing. This is responsible for the raising of atmospheric temperature.
- Industries and vehicles release gases like carbon monoxide and sulphur dioxide into the atmosphere, resulting in global warming and acid rain.