Changing State

The change between a solid, liquid and gas is a change of state. This is a physical change The particles themselves do not change in any way – only their movement and the amount of energy they have changes.

For a change of state to occur energy must be added or removed.

Expansion and Contraction Balloon Experiment

Expansion & Contraction Heating results in expansion. Cooling results in contraction. Heat energy effects the movement of the particles whether they be in solid, liquid or gas form.

Gaining Energy What happens to an ice cube if you leave it out in the sun? MELTING or LIQUEFYING refers to a solid becoming a liquid.

Gaining Energy What happens if you heat up a pot of water? BOILING or VAPORISING refers to a liquid turning into a gas.

Gaining Energy What is evaporation? EVAPORATION is vaporisation without boiling. Can you think of an example of evaporation taking place in everyday life?

Losing Energy What is happening when water droplets gather on the outside of a cold glass? CONDENSATION occurs when a gas turns to a liquid.

Losing Energy How does a liquid turn into a solid? FREEZING or SOLIDIFYING is the process of a liquid turning into a solid.

Sublimation Some substances sublime. This means they go from solid to gas without going through a liquid phase. The reverse is called deposition.