View your list of saved words. (You can log in using Facebook.)
In thermodynamics, a chemically and physically uniform quantity of matter that can be separated mechanically from a nonhomogeneous mixture. It may consist of a single substance or of a mixture of substances. The three basic phases of matter are solid, liquid, and gas; other phases that are considered to exist include crystalline (seecrystal), colloidal (seecolloid), glass, amorphous, and plasma. The different phases of a pure substance are related to each other in terms of temperature and pressure. For example, if the temperature of a solid is raised enough, or the pressure is reduced enough, it will become a liquid.
This entry comes from Encyclopædia Britannica Concise. For the full entry on phase, visit Britannica.com.