(a) Consider a substance where the intermolecular forces hold the molecules in fixed rigid positions. What is the process called when enough heat has been added to the substance so that the molecules begin to flow?
(b) Consider a substance where the intermolecular forces hold the molecules in close contact with each other, but the molecules can flow. What is the process called when enough heat has been added to the substance so that the molecules escape each other?
(c) Consider a substance where the intermolecular forces hold the molecules in fixed rigid positions. What is the process called when enough heat has been added to the substance so that the molecules can escape each other?