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).