A key result from quantum mechanics is that energy is quanti

A key result from quantum mechanics is that energy is “quantized.” What does that mean to us in thermodynamics? For example, what does that mean about how internal energy is stored in a gas?

Solution

From the point of view of quantum mechanics a quanta is a packet of energy.

Thermodynamics involves macroscopic bodies and not microscopic.

Internal energy is a function of temperature, so whenever a gas is heated, the temperature rises gradually. These gradual steps resmble the energy packets or the quanta which results in the increase of temperature and hence internal energy.