Phase changes always occur with a change in the average

Last updated: 7/31/2022

Phase changes always occur with a change in the average amount of heat in a system. Heat, which is a measure of energy, either is absorbed by the material during a phase change or is released by the material during the phase change. However, although the heat content of the material changes, the temperature does not change during a phase change. Classify the following phase changes as processes that require the input of energy, or as processes that have a net output of energy.