Unit Test Answers

During which changes of state do atoms overcome the attractive forces between them?

Brian made this table to organize his notes on changes of state.Which change of state has the wrong energy change listed?

A cylinder at left with balls evenly spaced throughout the cylinder has an arrow leading to a cylinder at right cylinder with balls stacked near its bottom.

What happens during evaporation?

On a cool morning, Uyen’s breath can form a cloud when she breathes out. Which changes of state are most responsible for Uyen seeing her breath in this way?

The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance lose energy during a change of state. Before the change, the atoms are close together but are able to slide past one another.

A cylinder at left with balls evenly spaced throughout the cylinder with an arrow leading to a cylinder at right with balls stacked near the bottom of the cylinder.

Which is the process by which a solid changes to a liquid?

As atoms gain energy, they move faster and slide past one another more easily. Atoms at the surface of the substance overcome attractions to nearby atoms and break free of the surface.

Freida wants to model the way atoms move when a substance changes its state. To do this, Freida makes a pyramid of marshmallows. Then, she knocked down the pyramid causing the marshmallows to fall.