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Phases of matter can be changed by a number of things. This includes 19 and temperature.
When a solid becomes a liquid, it is called 20 . When a solid becomes a gas, it is called
21 . When a liquid becomes a gas, it is called 22 (or vaporisation). When a gas becomes a liquid, it is called 23 . When a liquid becomes a solid, it is called
24 . The freezing point and the melting point are said to be the 25 , because any increase in temperature will cause it to 26 and any 27 in temperature will cause it to freeze. This is also the reason that the vaporizing and condensation 28 are the same.