What happens to particles when a substance gains energy and changes state?

When a substance gains energy and changes state, its particles absorb that energy, leading to increased kinetic energy. As a result, the particles move more rapidly and may overcome attractive forces holding them together. For instance, in melting, solid particles gain enough energy to break free from their fixed positions, transitioning to a liquid state. Similarly, in boiling, liquid particles gain sufficient energy to escape into the gas phase.