Describe the differences between the energy, spacing and movement of molecules in a solid, a liquid, and a gas. (5 marks)
Solid: In a solid, molecules are packed closely together in a fixed arrangement. They have a relatively low amount of energy and do not move around much.
Liquid: In a liquid, molecules are still close together but are able to move around each other. They have more energy than in a solid and can move around freely.
Gas: In a gas, molecules are spaced far apart and move around rapidly. They have the highest amount of energy and move around in random directions.