In thermodynamics, heat and temperature are distinct; which statement best describes their relationship?

• A. Heat is energy in transit; Temperature measures the average kinetic energy.
• B. Heat is stored energy; Temperature is energy transfer.
• C. Heat is a unit of energy; Temperature is energy transfer.
• D. They are the same.

Answer: (A)

Heat is energy in transit caused by a temperature difference, while temperature is a measure of the average kinetic energy of the particles in a substance. This means heat flows from hotter to cooler objects until thermal equilibrium is reached, and temperature tells us how energetic the particles are on average inside a system. The statement captures the dynamic nature of energy transfer (heat) and the properties of the system (temperature). The other descriptions mix up what heat and temperature represent: heat is not stored energy, nor is temperature energy transfer, and they are not the same thing.