In this lesson our instructor talks about the chemistry of solids. First, he discusses the basic structure of solids, crystal lattices, and lattice enthalpy. Then he talks about different types of crystalline solids, phase changes involving solids, and the phase diagrams. He ends the lesson with a summary and three helpful sample problems. The Chemistry of Solids The common unit cells for solids are primitive cubic, body-centered cubic, and face-centered cubic. The unit cell structure can influence a solid’s density and texture. Lattice energy is used to quantify the strength of the interaction within a crystalline solid. Phase diagrams are used to graphically predict a substance’s physical state at a set of pressure and temperature conditions.