Phase Change Flashcard

Front

What happens to molecules in a gas?

Back

They move away from each other.

Front

What determines whether a phase change occurs?

Back

The interaction between kinetic energy and molecular attraction.

Front

What happens during freezing?

Back

The kinetic energy decreases, and the attraction pulls molecules together.

Front

Why does a substance melt when heated?

Back

The kinetic energy increases enough to overcome the attraction.

Front

What allows a liquid to flow?

Back

Its molecules move around, not away from each other.

Front

What is kinetic energy?

Back

The energy that an object possesses due to its motion.

Front

What is molecular attraction?

Back

The force that pulls molecules together.

Front

What happens to the kinetic energy of molecules when a substance is heated?

Back

The kinetic energy increases.

Front

What is the difference between a solid and a liquid?

Back

In a solid, molecules are tightly packed and vibrate in place; in a liquid, molecules are close but can move around.

Front

What is evaporation?

Back

The process where molecules at the surface of a liquid gain enough energy to become gas.