Phase Change Exam

Front

What happens to molecular movement when a substance melts?

Back

The molecular movement increases.

Front

Are the molecules in a solid object always moving?

Back

Yes, the molecules are always moving.

Front

What causes a phase change in a substance?

Back

A phase change occurs when energy is transferred in and out of a substance, causing molecular movement to speed up or slow down.

Front

Do molecules in both water in a glass and water in the ocean move?

Back

Yes, both have molecules that are moving.

Front

What happens to molecules when their kinetic energy decreases?

Back

They move slower.

Front

Define 'phase change'.

Back

A phase change is a transition of matter from one state to another, such as solid to liquid or liquid to gas.

Front

What is kinetic energy?

Back

Kinetic energy is the energy an object has due to its motion.

Front

What happens to the temperature of a substance during a phase change?

Back

The temperature remains constant during a phase change, even though energy is being added or removed.

Front

What is the relationship between temperature and molecular movement?

Back

As temperature increases, molecular movement increases.

Front

What is an example of a phase change?

Back

Melting ice into water is an example of a phase change.