Columbia Encyclopedia

Search results

472 results found

Europa, in astronomy

(Encyclopedia)Europa yo͝orōˈpə [key], in astronomy, one of the 39 known moons, or natural satellites, of Jupiter. Magnetic-field data collected by the space probe Galileo in 2002 strongly indicated a liquid-wat...

sodium thiosulfate

(Encyclopedia)sodium thiosulfate, Na2S2O3, colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3·5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite o...

chlorate

(Encyclopedia)chlorate pərklōrˈāt, –klôrˈ– [key], salts of chloric acid, HClO3, and perchloric acid, HClO4, respectively. Perchlorates are safer to handle than chlorates; they are more stable when expos...

colloid

(Encyclopedia)colloid kŏlˈoid [key] [Gr.,=gluelike], a mixture in which one substance is divided into minute particles (called colloidal particles) and dispersed throughout a second substance. The mixture is also...

pressure

(Encyclopedia)pressure, in mechanics, ratio of the force acting on a surface to the area of the surface; it is thus distinct from the total force acting on a surface. A force can be applied to and sustained by a si...

liquefied petroleum gas

(Encyclopedia)liquefied petroleum gas or LPG, mixture of gases, chiefly propane and butane, produced commercially from petroleum and stored under pressure to keep it in a liquid state. The boiling point of liquefie...

cloaca

(Encyclopedia)cloaca klōāˈkə [key], in biology, enlarged posterior end of the digestive tract of some animals. The cloaca, from the Latin word for sewer, is a single chamber into which pass solid and liquid was...

polystyrene

(Encyclopedia)polystyrene pŏlˌēstīˈrēn [key], widely used plastic; it is a polymer of styrene. Polystyrene is a colorless, transparent thermoplastic that softens slightly above 100℃ (212℉) and becomes a v...

Sloane, T(homas) O'Conor

(Encyclopedia)Sloane, T(homas) O'Conor, 1851–1940, American scientist, lecturer, writer, and periodical editor, Ph.D. Columbia, 1876. Sloane was a member of the editorial staff of the Scientific American, where h...

nitric acid

(Encyclopedia)nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. It forms an a...