Of all water in the world, 97% is salty ocean water, 2% is polar ice and only a very small 1% is fresh water suitable for human needs.
The amount of water in the world remains constant and never changes (see the water cycle). As there is only 1% of fresh water available for use it is therefore sensible to make responsible use of such a vital resource. Nothing could survive on earth without water; not plants, animals or humans. The human body comprises of 2/3 water.
H2O The chemical composition of water is H2O. This means that it is a molecule made up of two hydrogen atoms and one oxygen atom.
There are three forms of water:
- Solid - snow, frost, hail and ice
- Gas - water vapour
- Liquid - clouds, rain, oceans, lakes, rivers, fog
Water fast facts:
- Water at 0° Celsius is at freezing point and forms ice
- Water at 100° Celsius is at boiling point
- Water can be found in the air. It is also part of the ground, trees, animals, fruit, vegetables, meat and our bodies
- The moisture contained in the atmosphere prevents the earth from becoming dry and hot
- We lose on average three litres of water per day that needs replenishing regularly
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