Difference between heat, thermal energy, and temperature

[Snazzy]

This isn't really a homework question per se. I'm studying for my MCAT and I'm having trouble trying to firmly get down some of the concepts in thermodynamics.

As far as I know, heat is the means of energy transfer that isn't work from one substance to another due to a difference in temperature between the two substances.

Thermal energy is the total amount of kinetic and potential energy in a substance.

Temperature is the average (per particle) amount of kinetic and potential energy in a substance.

So something that has a lower temperature, like a big chunk of ice, may have more thermal energy than something like a small heated nail.

Am I on the right track? I'm not too sure whether temperature/thermal energy is a measure of potential energy and kinetic energy, or just one or the other.

Thanks for your help.

 

[Ygggdrasil]

Thermal energy and temperature refer to kinetic energy, and not potential energy. For example, it when you add heat to ice at 0^oC, the heat does not change the thermal energy or temperature of the ice. Instead the heat changes the ice into water, increasing the potential energy of the water molecules.

 

[Snazzy]

Is not thermal energy also related to the potential energy of the molecules?

 

[Ygggdrasil]

It depends what you mean by thermal energy (I'm not so sure this is a well defined term). Certainly the internal energy and enthalpy of molecules are dependent on both the kinetic and potential energy of the molecules.