Demonstrates that Gibbs Free Energy is made up of enthalpy and entropy terms. Physical reality is illustrated by computer-generated models. Kinetic and potential energies of a crystal are shown by a ball and spring simulation, while in the same split-screen segment the binding energy of the atoms is depicted by a potential energy trough. As temperature is raised, amplitude of motion in the atoms increases, resulting in a change of phase. The split screen shows change in the disorder of the system. Variations caused by composition as well as temperature are viewed for both enthalpy and entropy. From the Phase equilibria series.