Question

what is the thermal energy of a system?
a. the average speed of molecules in a system
b. the total mass of molecules in a system
c. the number of molecules in a system
d. the total kinetic energy of the particles in a system

Explanation:

Thermal energy is related to the motion of particles. It is the total kinetic energy of the particles in a system due to their random motion. The average speed of molecules is related to temperature, mass and number of molecules alone do not define thermal energy.

Answer:

D. The total kinetic energy of the particles in a system