ABSTRACT
Classical statistical mechanics considers macroscopic systems with positions and momenta that can be arbitrarily close to one another. This chapter outlines the study of ideal gases using quantum statistical mechanics. The Sackur-Tetrode equation enables calculation of standard entropy values for ideal monatomic gases with given atomic masses. The chapter elaborates on the thermodynamic properties of quantum ideal gases. The quantum mechanical description of a system is probabilistic, and is described by a wave function that contains information about the interactions between its constituents. Somewhat mysteriously, a system's behaviour depends on whether the quantum spins of the constituent molecules are integers or half integers. In 1912, Peter Debye generalised Einstein's model of a solid. The Debye solid has improved low temperature behaviour. An activity that shows the properties of rubber is to quickly stretch and contract a rubber band. These properties are attributable to the fact that rubber is a polymer.
