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Tokat

(Encyclopedia)Tokat tōkätˈ [key], city (1990 pop. 83,174), capital of Tokat prov., N central Turkey. It is an agricultural market with copper manufactures. An important town in Roman times, it declined under the...

Zewail, Ahmed Hassan

(Encyclopedia)Zewail, Ahmed Hassan, 1946–2016, Egyptian-American chemist, b. Damanhur, Egypt, Ph.D. Univ. of Pennsylvania, 1974. He became a U.S. citizen in 1982. A professor at the California Institute of Techno...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

phosphorus

(Encyclopedia)phosphorus fŏsˈfərəs [key] [Gr.,=light-bearing], nonmetallic chemical element; symbol P; at. no. 15; at. wt. 30.97376; m.p. 44.1℃; b.p. about 280℃; sp. gr. 1.82 at 20℃; valence −3, +3, or ...

Mufulira

(Encyclopedia)Mufulira mo͞ofo͞olēˈrä [key], city (1990 pop. 152,944), N central Zambia, on the border with the Congo. It is a copper-mining center, located in the Copperbelt. ...

Erzgebirge

(Encyclopedia)Erzgebirge ĕrtsˈgəbĭrˌgə [key] [Ger.,=ore mountains], Czech Krušné Hory, mountain range, along the Czech–German border, extending c.95 mi (150 km) from the Fichtelgebirge in the southwest to...

electrode

(Encyclopedia)electrode, terminal through which electric current passes between metallic and nonmetallic parts of an electric circuit. In most familiar circuits current is carried by metallic conductors, but in som...

protein

(Encyclopedia)protein, any of the group of highly complex organic compounds found in all living cells and comprising the most abundant class of all biological molecules. Protein comprises approximately 50% of cellu...

Köthen

(Encyclopedia)Köthen köˈtən [key], city (1994 pop. 31,860), Saxony-Anhalt, central Germany. Köthen has lignite mines, sugar refineries, textile mills, chemical factories, and heavy engineering industries. The ...

Chain, Ernst Boris

(Encyclopedia)Chain, Ernst Boris, 1906–79, English biochemist, b. Berlin, Germany. In 1933 he left Germany and went to England, where he conducted research at Cambridge from 1933 to 1935 and at Oxford from 1935; ...