thermal energy

This term is used primarily in scientific and technical contexts to describe the total kinetic energy of particles within a substance. It is distinct from temperature, which measures the average kinetic energy; while temperature describes the intensity of heat, thermal energy describes the total quantity.

As a mass noun representing a physical property, it is treated as uncountable. It does not take a plural form and cannot be counted with numbers, requiring quantifiers such as "amount of" or "level of" when referring to quantity.