They vibrate quickly in place. They spread apart to fill their container. They move at the same speed as in a liquid. They move slowly over one another.
I gave my students this multiple choice question: Which best describes the motion of molecules in the gaseous state?

Only one answer is correct among these 4 choices:
- They vibrate quickly in place.
- They spread apart to fill their container.
- They move at the same speed as in a liquid.
- They move slowly over one another.

Could you tell me which one is correct?

They spread apart to fill their container.