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sediment

(Encyclopedia)sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments form sedimentary ...

atomic weight

(Encyclopedia)atomic weight, mean (weighted average) of the masses of all the naturally occurring isotopes of a chemical element, as contrasted with atomic mass, which is the mass of any individual isotope. Althoug...

detonator

(Encyclopedia)detonator dĕˈtənāˌtər [key], type of explosive that reacts with great rapidity and is used to set off other, more inert explosives. Fulminate of mercury mixed with potassium chlorate is a common...

Coleraine

(Encyclopedia)Coleraine kōlrānˈ [key], town and district, N Northern Ireland, near the mouth of the Bann ...

Cherepovets

(Encyclopedia)Cherepovets chĕrĭpəvyĕtsˈ, chĕrĭpôˈvyĭts [key], city (1989 pop. 310,000), NE European Russia, on the Rybinsk Reservoir. A rail and water transportation center of the Volga-Baltic Waterway, i...

Chaptal, Jean Antoine

(Encyclopedia)Chaptal, Jean Antoine zhäN äNtwänˈ shäptälˈ [key], 1756–1832, French chemist, industrialist, and statesman. He became (1781) professor of chemistry at Montpellier, and during the Revolution h...

Helmont, Jan Baptista van

(Encyclopedia)Helmont, Jan Baptista van yän bäptĭsˈtä vän hĕlˈmônt [key], 1577–1644, Flemish physician, chemist, and physicist. He attributed physiological changes to chemical causes, but his conclusions...

Hefei

(Encyclopedia)Hefei or Hofei both: hô-fā [key], city (1994 est. pop. 866,800), capital of Anhui prov., China. A rapidly growing industrial city, it has textile mills, ironworks and steelworks, chemical and food p...

Heyrovsky, Jaroslav

(Encyclopedia)Heyrovsky, Jaroslav, 1890–1967, Czech chemist, Ph.D. Charles Univ. of Prague, 1918; D.Sc. University College, London, 1921. Heyrovsky was director of the Polarography Institute at the Czechoslovak A...

Hodgkin, Sir Alan Lloyd

(Encyclopedia)Hodgkin, Sir Alan Lloyd, 1914–98, English biophysicist. For their work in analyzing the electrical and chemical events in nerve-cell discharge, he and Andrew Huxley shared with Sir John Eccles the 1...