Question

Juan noticed that a door that sticks on hot days does not stick when it cools off at night. This is because the metal contracts as it cools. The reason for this is that, as the metal cools, the atoms:

become smaller and take up less space .

slow down and move closer together.


merge together to form fewer atoms.


speed up and move further apart.

Answer 1

The atoms in the metal slow down and move closer together. So the answer is B.