Answer: The appearance of the substance before the phase change can be described as Melting, Vaporization, Sublimation, Condensation.
Melting:
When a substance converts from the solid to the liquid.
Vaporization:
The substance changes from a liquid to a gas.
Condensation:
When a substance converts from a gas to a liquid.
Sublimation:
When a substance converts directly from a solid to a gas without going through the liquid phase.
Therefore, the appearance of the substance before the phase change can be described as Melting, Vaporization, Sublimation, Condensation.
