12 Useful facts you must know about water

Summary

1. Water occurs in nature and nearly three-fourths of the earth’s surface is covered with water.

2. Water is essential for life.

3. Rain water collects on earth in the form of surface water and underground water.

4. Drinking water should be free from germs and suspended impurities.

5. The constant movement of water from the earth to the air and back to the earth is known as the water cycle.

6. A water molecule is made up of two atoms of hydrogen and one atom of oxygen.

7. Water exists in solid, liquid and gaseous states. It is colourless, tasteless, odourless and transparent.

8. Pure water boils at 100°C and freezes at 0°C. The maximum density of water is 1 gm/cm1 at 4°C.

9. Water is a universal solvent as a large number of solids, liquids and gases dissolve in it.

10. Hard water contains dissolved salts of calcium or magnesium. It does not lather with soap.

11. Soft water lathers well with soap.

12. Water should be conserved and saved from pollution.