Heat capacity is defined as what?

• A. Raise whole object by 1°C.
• B. Raise 1 gram by 1°C.
• C. The rate of heat transfer.
• D. The total energy stored in the object.

Answer: (A)

Heat capacity is the amount of heat needed to raise the temperature of the entire object by 1 degree. That means the best choice says you must add a certain amount of energy to the whole object to increase its temperature by 1°C, and that amount depends on the object's mass and material. For example, if an object has a heat capacity of 200 J/°C, raising its temperature by 1°C requires 200 joules of heat. The other ideas aren’t definitions of heat capacity: raising just 1 gram by 1°C corresponds to a specific amount of heat per gram (the material’s specific heat), not the whole object’s capacity; the rate of heat transfer describes how fast heat moves, not how much heat it takes to change temperature; and the total energy stored in the object refers to internal energy, not how much energy is needed to raise its temperature.