Wiktionary
change of state
n. Any change of a substance from one physical state (solid, liquid or gas) to another
WordNet
change of state
n. the act of changing something into something different in essential characteristics
Usage examples of "change of state".
Death was a change of state to the people of the Clan, a journey to another plane of existence.
For whenever a thing changes and quits its proper limits, at once this change of state is the death of that which was before.