20.5 Thermal Energy and Specific Heat

We defined the thermal energy of a system to be $E_{\text{th}}=K_{\text{micro}}+U_{\text{micro}}$, where $K_{\text{micro}}$ is the microscopic kinetic energy of the moving molecules and $U_{\text{micro}}$ is the potential energy of the stretched and compressed molecular bonds. A microscopic look at thermal energy will allow us to predict the molar specific heat, a macroscopic state variable.