Imagine that you can see individual molecules. You watch a small collection of molecules that are moving around slowly while vibrating and bumping against each other. The slower moving molecules then start to line up, but as they do so their vibrations increase. Soon all the molecules are aligned and vibrating about fixed positions. What is happening?
A)The sample is being cooled and the material is freezing.
B)The sample is being heated and the material is boiling.
C)The sample is being cooled and the material is condensing.
D)The sample is being heated and the material is melting.
E)The sample is unchanged.

Question

Quizplus · Accepted Answer

When the molecules start to line up and vibrate about fixed positions, it suggests that the material is losing energy and cooling down. This is a characteristic of freezing, where a liquid material becomes a solid as it loses thermal energy and its molecules take on fixed positions.

Imagine That You Can See Individual Molecules