Question

which refers to the thermal energy that flows from one substance to another when the substances differ in temperature?
heat
temperature
convection
flow

Explanation:

Heat is defined as the thermal energy that transfers from a substance at a higher - temperature to a substance at a lower - temperature due to the temperature difference. Temperature is a measure of the average kinetic energy of particles in a substance. Convection is a mode of heat transfer, not the thermal energy itself. Flow is a general term and not specific to thermal energy transfer due to temperature differences.

Answer:

A. heat