solid
Solid is a state of material existence, is one of the four basic material state. Compared with the liquid and gas, the solid has a fixed volume and shape, the shape does not change with the shape of the container. The texture of the solid is stronger than the liquid and the gas is hard and the solid atoms are tightly bonded. The solid may be crystal, and its spatial arrangement is a regular lattice arrangement (such as metal and ice), or it may be an amorphous body, which is irregularly arranged in space (for example, glass). In general, the solid is a macro object, an object to reach a certain size can be called a solid, but its size is not clear. The study of solid branches in physics is called solid-state physics and is one of the main branches of condensed matter physics. Materials Science discusses the physical and chemical properties of various common solids. Solid chemistry studies of a chemical branch of solid structure, properties, synthesis, characterization, and so on, are also related to the chemical synthesis of some solid materials. ...