The bulk of solid-state physics, as a general theory, is focused on crystals. Depending on the material involved and the conditions in which it was formed, the atoms may be arranged in a regular, geometric pattern ( crystalline solids, which include metals and ordinary water ice) or irregularly (an amorphous solid such as common window glass). hardness and elasticity), thermal, electrical, magnetic and optical properties of solids. These interactions produce the mechanical (e.g.
Solid materials are formed from densely packed atoms, which interact intensely.
