3.3 Solids, Liquids, and Gases

Solids have both a definite shape and a definite volume. They may be crystalline, meaning the particles are arranged in an ordered three-dimensional pattern, or amorphous, meaning there is no long-range regular structure. For example, sodium chloride forms a crystal lattice, while glass is an amorphous solid. In solids, particles are held in fixed positions and cannot move freely relative to one another. The strength of the forces or bonds between particles influences how closely packed they are, which in turn affects density. Solids are mainly held together by chemical bonds.