Water is all round us. It is in the air, in and on the ground, in everything we eat or drink, in animals, in man, in plants, just everywhere. Eighty percent of the earth's surface is water in some form. These three forms are

1. Liquid

a. Saltwater - oceans (97 percent of all the water on earth)
b. Freshwater - lakes, streams, rivers, ponds, wells;
c. Groundwater - (1 percent of all the water on earth

2. Solid

Glaciers, icebergs, ice, snow - (2 percent of water on earth

3. Gas

Vapour in the air, clouds

Water as precipitation, exists in the same three forms:

  • Liquid
    Rain, Sleet, Drizzle
  • Solid
    Snow, Hail
  • Gas

Liquid (water) becomes solid (ice) when the temperature of the water is below freezing (O degrees Celsius). Frozen water becomes strong enough to walk or skate on because the molecules of water are now holding very tightly to one another

Water expands when it freezes. It can break bottles and pipes and cause cracks in rocks and pavements. As ice melts, molecular bonds loosen and it becomes a fluid (water).

When water is heated to boiling point (100 degrees celsius), the molecular bonds break and the water becomes a gas (steam). Steam exerts a powerful force when constricted and can be used to drive machinery