Which term is defined as the energy associated with the motion of atoms or molecules within a fuel, transferred from one body to another due to a temperature difference between the bodies?

• A. Combustion
• B. Fire
• C. Heat
• D. Chemical reaction

Answer: (C)

Heat is the energy in transit from a hotter object to a cooler one because of a temperature difference. The energy tied to the microscopic motion inside a fuel (thermal energy or internal energy) exists within the substance, but heat refers specifically to the transfer of that energy between bodies due to their temperature difference. In other words, heat is what flows to even out temperatures.

Options like combustion, fire, or a chemical reaction describe processes that release or involve chemical changes, not the simple transfer of energy caused by a temperature gradient.