Any change of a substance from one physical state (solid, liquid or gas) to another(noun)
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Use "change of state" in a sentence
"Natural roan would fain be his own Saviour; and supposeth a change of state to be a thing within his own power; and that the true work of grace lieth in leaving off the practice of sin, and taking up a life of duties: and, therefore, upon this principle, doth many a graceless professor outstrip a sound believer; for he resteth on his own performances, and hopeth these will commend him to God."