What is a phase change physics?
Furthermore, what do you mean by phase change?
phase change - a change from one state (solid or liquid or gas) to another without a change in chemical composition. phase transition, physical change, state change. freeze, freezing - the withdrawal of heat to change something from a liquid to a solid. liquefaction - the conversion of a solid or a gas into a liquid.
Then, what are the phase changes that require energy?
Phase changes require either the addition of heat energy (melting, evaporation, and sublimation) or subtraction of heat energy (condensation and freezing).
Substances on Earth can exist in one of four phases, but mostly, they exist in one of three: solid, liquid or gas. Learn the six changes of phase: freezing, melting, condensation, vaporization, sublimation and deposition.