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States of matter

Solids, liquids and gases are called the three states of matter.

Materials can be changed from one state to another by heating or cooling.


  • If ice (solid) is heated, it changes to water (liquid). This change is called melting.

  • Water (liquid) can change to water vapour (gas). This is called evaporation.

  • If water (liquid) is heated until it boils, it changes to water vapour (gas) very quickly. Water boils at 100°C


  • If water vapour (gas) is cooled, it changes to water (liquid). This change is called condensing.

  • If water (liquid) is cooled, it changes to ice (solid). This change is called freezing. Water freezes at 0°C

Illustration showing the three states of matter: Solid (ice), liguid (water) and gas (steam), amd the processes that create them

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