The free electron model is the solid state equivalent of the familiar particle in a box model from physical chemistry. We set the basis set of the wavefunction to a constant value which reduces the wavefunction to eikx. The single band that comes out of this approach is similar in many ways to the band structures of solids made solely from hydrogen atoms. The Fermi-Dirac function and Fermi velocity are introduced. The lecture finishes with a closer look at the conductivity of metals, including transition metals. This lecture was designed and delivered by Patrick Woodward for use in the course Solid State Chemistry (Chem 7330) at Ohio State University.