Water is one of the basic substances present on the earth. It plays a vital role in the evolution and survival of life; it is impossible to imagine life on the earth without water. Water helps to regulate the temperature of our planet and also helps to maintain the temperature in organisms. This chapter covers the sources, availability and composition of water, the water cycle, conservation of water and the work of Lavoisier.
1. Sources and Forms of Water
We need water for day-to-day activities like cooking food, washing clothes and cleaning utensils. In villages and towns, wells, canals, tanks, ponds, rivers, water tanks and hand pipes are the main sources of water.
Three Forms of Water in Nature
| Form | Name | Where it is present |
|---|---|---|
| Solid | Ice | Ice bergs and ice caps on top of tall mountains, glaciers and polar regions |
| Liquid | Water | Oceans, seas, lakes, rivers and even underground |
| Gaseous | Vapour | The air around us |