What is the term for the ability of an object to store thermal energy?

• A. Thermal Capacity
• B. Thermal Diffusivity
• C. Thermal Conductivity
• D. Specific Heat

Answer: (A)

Thermal capacity, also called heat capacity, is the measure of how much energy an object can store for a given change in temperature. It tells you how much heat must be added to raise the object's temperature by one degree. The relationship Q = C × ΔT means that the stored energy depends on both the temperature change and the object's capacity to store heat. A larger thermal capacity means more energy can be stored with the same temperature increase.

Specific heat describes energy per unit mass per degree, so it’s about how much energy a material can store per kilogram, not the total energy for the whole object unless you multiply by mass. Thermal diffusivity and thermal conductivity relate to how quickly heat moves through a material, not how much energy can be stored. So the term that fits the question is thermal capacity.