Columbia Encyclopedia

Search results

302 results found

beer, alcoholic beverage

(Encyclopedia)beer, alcoholic beverage made by brewing and fermenting cereals, especially malted barley, usually with the addition of hops as a flavoring agent and stabilizer. One of the oldest of alcoholic beverag...

Bohr, Niels Henrik David

(Encyclopedia)Bohr, Niels Henrik David bōr [key], 1885–1962, Danish physicist, one of the foremost scientists of modern physics. He studied at the Univ. of Copenhagen (Ph.D. 1911) and carried on research on the...

steam engine

(Encyclopedia)CE5 Steam engine steam engine, machine for converting heat energy into mechanical energy using steam as a medium, or working fluid. When water is converted into steam it expands, its volume increa...

determinant

(Encyclopedia)determinant, a polynomial expression that is inherent in the entries of a square matrix. The size n of the square matrix, as determined from the number of entries in any row or column, is called the o...

chemical equilibrium

(Encyclopedia)chemical equilibrium, state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen gas, H2, and iod...

charcoal

(Encyclopedia)charcoal, substance obtained by partial burning or carbonization (destructive distillation) of organic material. It is largely pure carbon. The entry of air during the carbonization process is control...

halogen

(Encyclopedia)halogen hălˈəjĕn [key] [Gr.,=salt-bearing], any of the chemically active elements found in Group 17 of the periodic table; the name applies especially to fluorine (symbol F), chlorine (Cl), bromin...

molybdenum

(Encyclopedia)molybdenum məlĭbˈdənəm [key] [Gr.,=leadlike], metallic chemical element; symbol Mo; at. no. 42; at. wt. 95.96; m.p. about 2,617℃; b.p. about 4,612℃; sp. gr. 10.22 at 20℃; valence +2, +3, +4...

sulfate

(Encyclopedia)sulfate, chemical compound containing the sulfate (SO4) radical. Sulfates are salts or esters of sulfuric acid, H2SO4, formed by replacing one or both of the hydrogens with a metal (e.g., sodium) or a...

Trieste

(Encyclopedia)Trieste trēĕˈstā [key], Serbo-Croatian Trst, city (1991 pop. 231,100), capital of Friuli–Venezia Giulia and of Trieste prov., extreme NE Italy, on the Gulf of Trieste (at the head of the Adriati...