Question

describing thermal equilibrium
what occurs at thermal equilibrium?
heat flows from the higher - temperature substance to the lower - temperature substance.
heat flows from the lower - temperature substance to the higher - temperature substance.
heat does not flow because both substances are at the same temperature.

Explanation:

Thermal equilibrium is a state where there is no net heat transfer between two substances. Heat transfer occurs from a higher - temperature substance to a lower - temperature one until thermal equilibrium is reached. At thermal equilibrium, the temperatures of the two substances are equal. So, heat does not flow because both substances are at the same temperature.

Answer:

Heat does not flow because both substances are at the same temperature.