According to many sources, internal energy is the kinetic and potential energies of molecules of a substance – combined. Some sources also say that thermal energy is that definition.
However, I don’t think that thermal energy is kinetic and potential energy combined. I know that heat transfer occurs between a region with higher temperature and a region with lower temperature, but it isn’t necessarily the case with tworegions of different internal energies. So that seems to imply to me that temperature is a measurement of thermal energy – so in that sense thermal energy is merely the average kinetic energy of molecules and as such, doesn’t include the potential energy. Is that right?