Question

what is the definition of thermal equilibrium
a measure of the average kinetic energy of an objects particles
the process of thermal energy transfer by electromagnetic waves
state in which all parts of a system are at the same temperature
condition caused by the loss of too much body heat

Explanation:

Thermal equilibrium is a state in a system where there is no net heat transfer between its parts. This occurs when all parts of the system reach the same temperature.

Answer:

state in which all parts of a system are at the same temperature