Columbia Encyclopedia

Search results

500 results found

law of simple multiple proportions

(Encyclopedia)law of simple multiple proportions, in chemistry, the statement that when two or more elements form more than one compound, the ratio of the weights of one element that combine with a given weight of ...

photocopying

(Encyclopedia)photocopying, process whereby written or printed matter is directly copied by photographic techniques. Generally, photocopying is practical when just a few copies of an original are needed. When many ...

Dead Sea

(Encyclopedia)Dead Sea, salt lake, c.390 sq mi (1,010 sq km), extending c.45 mi (70 km) in the Jordan trough of the Great Rift Valley between the Ghor on the north and Wadi Arabah on the south, on the border betwee...

Calvin, Melvin

(Encyclopedia)Calvin, Melvin, 1911–97, American organic chemist and educator, b. St. Paul, Minn., grad. Michigan College of Mining and Technology, 1931, Ph.D. Univ. of Minnesota, 1935. In 1937 he joined the facul...

Cornforth, Sir John Warcup

(Encyclopedia)Cornforth, Sir John Warcup wôrˈkəp côrnˈfərth [key], 1917–2013, Australian chemist, Ph.D. Oxford, 1941. Although Cornforth suffered a hearing loss from childhood and was deaf by the time he gr...

Bountiful

(Encyclopedia)Bountiful, city (2020 pop. 43,893), Davis co., N central Utah; inc. 1892. It is a residential suburb N of Salt Lake City with some farming and floral nu...

Prince Edward Island National Park

(Encyclopedia)Prince Edward Island National Park, 7 sq mi (18 sq km), NW P.E.I., Canada, on the Gulf of St. Lawrence; est. 1937. It extends 25 mi (40 km) along the coast and contains sand dunes, cliffs, salt marshe...

Ndjamena

(Encyclopedia)Ndjamena fôr-lämēˈ [key], city (1993 urban pop. 213,342), capital of Chad and of Chari-Baguirmi prefecture, SW Chad. It is a port on the Chari River and a transportation hub that lies on roads lea...

Margarita

(Encyclopedia)Margarita märgärēˈtä [key], island, 444 sq mi (1,150 sq km), in the Caribbean Sea off the coast of Venezuela. With many smaller islands it constitutes the Venezuelan state of Nueva Esparta (1990 ...

precipitation, in chemistry

(Encyclopedia)precipitation, in chemistry, a process in which a solid is separated from a suspension, sol, or solution. In a suspension such as sand in water the solid spontaneously precipitates (settles out) on st...