Energy must be added or removed in order for a sub-stance to change its physical state The six ways to change the phase (state) of matter) Melting changes a solid to a liquid. lake freezing over) 3) Evaporation changes a liquid to a gas. The temperature of a substance is related to the speed of the substance’s particles. Change of State A. Losing or Gaining Energy When most substances lose or gain energy, one of two things happens to the substance: its temperature changes or its state changes. (