At 25°C, they have more mass. At 25°C, they are moving faster. At 25°C, they have less kinetic energy. At 25°C, they are decreasing in volume.
I gave my students this multiple choice question: Perfume sprayed from a bottle spreads more easily in a warm room of 25°C than in a cool room of 15°C. Which of the following correctly compares perfume molecules at 25°C to those at 15°C?

Only one answer is correct among these 4 choices:
- At 25°C, they have more mass.
- At 25°C, they are moving faster.
- At 25°C, they have less kinetic energy.
- At 25°C, they are decreasing in volume.

Could you tell me which one is correct?

At 25°C, they are moving faster.