Internal Energy from Pressure and Volume in an Ideal Gas
For a monoatomic ideal gas, the internal energy is defined as the total kinetic energy of its constituent particles, since no other energy modes (vibrational, chemical, electronic) are present. Kinetic theory relates this microscopic quantity to macroscopic state variables via the derivation U = (3/2)PV, which combines with the ideal gas law PV = nRT to give U = (3/2)nRT. This establishes internal energy as a state function dependent only on temperature (and particle number) for an ideal gas, belonging to the domain of thermodynamics and kinetic theory of gases.
Internal Energy from Pressure and Volume in an Ideal Gas
For a monoatomic ideal gas, the internal energy is defined as the total kinetic energy of its constituent particles, since no other energy modes (vibrational, chemical, electronic) are present. Kinet…