AIR AND WATER
Air and Water
- Atmosphere is the blanket of air that surrounds the earth.
- Part of atmosphere nearest to the earth is troposphere layer, beyond troposphere is
- Air is a mixture of gases containing 78% of nitrogen, 21% of oxygen and 1% of other gases including carbon dioxide. It also contains dust, smoke and water vapour.
The Layers of the Atmosphere
- Air has weight; it occupies space and exerts pressure in all the directions.
- Water is very important to all living things. The substances that make water unfit for consumption are called impurities. Harmful impurities of water have to be removed to make it fit for drinking.
- Sedimentation, decantation and filtration are used for removing insoluble impurities of water. Distillation is used to remove soluble impurities, chlorine is added to kill germ and help to make the water safe for drinking