Phase Change Practice Questions

Front

What is a phase change?

Back

A phase change is a transition of matter from one state (solid, liquid, gas) to another due to the addition or removal of energy.

Front

What happens to molecules during a phase change from solid to liquid?

Back

The molecules gain energy, move faster, and overcome some of the attractions between them, allowing them to flow.

Front

What is the effect of temperature on the phase of a substance?

Back

Increasing temperature generally adds energy to a substance, potentially causing it to change from solid to liquid (melting) or from liquid to gas (evaporation).

Front

What is the difference between evaporation and boiling?

Back

Evaporation occurs at the surface of a liquid at any temperature, while boiling occurs throughout the liquid at a specific temperature (boiling point).

Front

What happens to molecules during condensation?

Back

During condensation, molecules lose energy, move slower, and come closer together, transitioning from gas to liquid.

Front

What is the role of energy in phase changes?

Back

Energy is required to change a substance's phase; adding energy can cause melting or evaporation, while removing energy can cause freezing or condensation.

Front

What is the state of matter where molecules are tightly packed and vibrate in place?

Back

Solid.

Front

What is the state of matter where molecules are close together but can move around each other?

Back

Liquid.

Front

What is the state of matter where molecules are far apart and move freely?

Back

Gas.

Front

What is melting?

Back

Melting is the phase change from solid to liquid, occurring when a solid absorbs enough energy to overcome molecular attractions.