The above graph is a phase change diagram for water. At points B and D the water is going through a phase change. During the phase changes, what is happening to the temperature and the heat energy?

Question

Type Answer HERE:
The temperature and the heat energy are increasing during a phase change.
The temperature remains constant and the heat energy is increasing during a phase change.
The temperature is increasing and the heat energy remains constant during a phase change.
The temperature and the heat energy remain constant during a phase change

Answer 1

The correct answer is: The temperature remains constant and the heat energy is increasing during a phase change.

During a phase change, such as melting or boiling, the temperature of the substance does not change; instead, heat energy is added or removed to facilitate the change of state (from solid to liquid, or from liquid to gas, for example).