freezing and melting - when a substance is heated, energy is being transferred to the particles of the substance, making them vibrate. the more the particles vibrate, the weaker the bonds between the particles become so the particles can move around more, detemining their new state.
- when a substance is cooled, particles loose energy which prevents them from vibrating. the less the particles vibrate the strong the bonds between them become and the less the particles are able to move so the substance would be close to a solid.when a substance goes from a liquid to gas, it can go one of two ways ; boiling and evaporating How boiling is different to evaporating:
boiling-
requires a certain temperature
requires heat
bubbles of gaseous particles are formed
occurs throughout entire substance
evaporation-
can occur at all temperatures
no bubbles are formed
occurs only at the surface of substance