Internal Energy

Temperature: Temperature is a measure of average kinetic energy within a substance. It indicates how fast molecules are moving on average.

Thermal Equilibrium: Thermal equilibrium occurs when two objects or systems reach the same temperature and there is no net flow of thermal energy between them.

Specific Heat Capacity: Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount. It is a property that depends on the type of material.