Question

matter does not gain or lose mass during phase changes, this describes--- conservation of mass in phase changes phase transition theory law of conservation of energy mass - energy equivalence

Explanation:

The conservation of mass states that mass is neither created nor destroyed in a chemical or physical process like phase - changes. Phase transition theory deals with the change of state, not specifically mass conservation. The law of conservation of energy is about energy, not mass. Mass - energy equivalence relates mass and energy but is not about mass conservation during phase changes.

Answer:

Conservation of mass in phase changes