Nonliquids

Nonliquids are all states of matter that are not liquids. The term encompasses solids, gases, plasmas, and other phases that do not exhibit the fluidity and fixed volume typical of liquids. The properties of nonliquids depend on how their particles are arranged, how much energy they have, and the pressure and temperature of their environment.

Solids retain a definite shape and volume. Their particles vibrate around fixed positions in a crystalline lattice or in a disordered network. Solids can be hard, soft, brittle, or elastic, and their mechanical properties govern how they respond to forces. Examples include ice, metals, minerals, and ceramics.

Gases have neither fixed shape nor fixed volume; they expand to fill their container and are highly compressible. Particles move rapidly and interact mainly through collisions, making gases easy to mix and diffuse. Examples include air, nitrogen, and carbon dioxide at room conditions.

Plasmas are ionized gases containing free electrons and positive ions. They conduct electricity and respond to magnetic and electric fields, exhibiting collective behavior. Plasmas are common in stars, lightning, fluorescent lighting, and fusion experiments.

Beyond these, nonliquids include exotic and extreme states such as Bose-Einstein condensates and fermionic condensates at very low temperatures, degenerate matter in compact stars, and quark-gluon plasma at extreme energy densities. Some states, like supercritical fluids, are fluids that are not liquids and are therefore classified as nonliquids in this broad sense.

Phase transitions between nonliquids and liquids occur under changes in temperature and pressure, as shown on phase diagrams.