Question

Phase changes occur

A) as the temperature remains the same.
B) as the temperature decreases.
C) as the temperature increases.
D) all of the above
E) none of the above

Answer 1

Phase changes occur at fixed temperatures, which are the boiling and freezing points of substances. During the phase change, the process is isothermal, maintaining a constant temperature until the transition between the phases is complete.

Step-by-step explanation:

Phase changes occur at fixed temperatures for a given substance at a given pressure. These temperatures are known as the boiling and freezing (or melting) points for that substance. During a phase change, the temperature of a substance does not change. Thus, phase changes are considered isothermal, which means they occur at a constant temperature. For instance, when ice melts to water at 0°C, it remains at that temperature until the entire amount of ice has melted. Similarly, water boils at its boiling point and stays at that temperature until it has all turned to steam.

The correct answer to the student's question is A) as the temperature remains the same, because during the actual transition between phases, like from solid to liquid or liquid to gas, the temperature of the substance does not increase or decrease until the phase change is complete.