Science- water

Electrolysis Of Water:The chemical name for water is hydrogen

oxide, which obviously means it is a compound.

A Scientist called Henry Cavendish proved that water isn't an element. By splitting water into it's elements hydrogen and

oxygen. He did this by passing electricity through water using a Hoffmann

voltmeter.

Electrolysis:

Electrolysis is the splitting up of a compound by passing electricity

through it.Water = Hydrogen + oxygen

Expansion Of Water:

As a general rule all substances expand when heated and contract when cooled. Water

behaves as expected until it is cooled to 4ºC. On further cooling it actually expands!

Properties Of Water:

Water freezes at 0ºC. Ice will melt to form water at 0ºC. Thus 0ºC is the freezing point of water and the melting point of ice.

Water is an excellent solvent. A huge variety of substances dissolves in it.

Water is colourless, odourless liquid. The boiling point of water is 100ºC

The Water treatment:1. Screening: The water passes through screens or

meshes which trap any floating material.

2. Settling: water is stored in large reservoirs where heavy particles settle at the bottom.

3. Filtration: The water passes up through thick beds of sand. Any remaining insoluble particles are removed from the water.

4. Chlorination: Chlorine is now added to kill any bacteria that may be present.

5. Fluoridation: fluoridation is added to help prevent tooth decay.