In an investigation, the atoms of a certain substance lose energy during a change of state. Before the change, the atoms are far apart and move constantly at high speeds and in all directions. After the change, the atoms are close together but are able to slide past one another.

Question

Use the diagram that shows changes of state between solid, liquid, and gas to answer the question.

A diagram has a triangle at center with gas on top, liquid on bottom right, solid on bottom left. An arrow from gas to liquid is labeled O, and an arrow from liquid to gas is labeled N. An arrow from solid to liquid is labeled P, and an arrow from liquid to solid is labeled Q. An arrow from solid to gas is labeled L, and an arrow from gas to solid is labeled M.

Which arrow represents the substance’s change of state?

L
N
O
P

Answer 1

The scenario you described indicates that the atoms of the substance lose energy during a change of state, which suggests a transition from a gaseous state to a liquid state. In the diagram you provided:

• The arrow labeled O represents the transition from gas to liquid, where the substance loses energy.
• The arrow labeled N represents the transition from liquid to gas, where the substance gains energy.

Since you mentioned that the atoms lose energy and move closer together during the change of state, the correct answer is:

O (the arrow from gas to liquid).