Changes of State

Which statement best describes the energy changes associated with evaporation and boiling?

• Atoms gain energy during evaporation and boiling.

• Atoms lose energy during evaporation and boiling.

• Atoms gain energy during evaporation but lose energy during boiling.

• Atoms lose energy during evaporation but gain energy during boiling.

The process by which a solid changes to a liquid is

If atoms ___________ energy during a change of state, they are pulled together by attractive forces and become more organized.

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.

Which arrow represents the change of state described above?

• M

• N

• P

• Q

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

• freezing and condensation

• boiling and deposition

• condensation and melting

• vaporization and sublimation

During which change of state would the volume of a substance increase the most?

• deposition

• melting

• vaporization

• sublimation

Rahul sees a flock of birds. He watches as the flying birds land in neat little rows on several power lines. Which change of state does the motion of the birds most closely model?

• melting

• vaporization

• deposition

• sublimation

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.

Which change of state is taking place?

• liquid to gas

• gas to liquid

• liquid to solid

• solid to liquid

The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance gain energy during a change of state. Before the change, the atoms are close together and cannot slide past one another. After the change, the substance can fill its container.

Which arrow represents the change of state described above?

• L

• M

• N

• O

In which changes of state do atoms lose energy? Check all that apply.

• sublimation

• freezing

• boiling

• condensation

• deposition