Columbia Encyclopedia

(Encyclopedia) hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...

(Encyclopedia) Aragón ârˈəgŏn, Span. ärägōnˈ [key], autonomous community, 18,425 sq mi (47,720 sq km), and former kingdom, NE Spain, bordered on the N by France. The city of Z...

(Encyclopedia) low-temperature physics, science concerned with the production and maintenance of temperatures much below normal, down to almost absolute zero, and with various phenomena that occur only at such tempe...

(Encyclopedia) cigar and cigarette, tubular rolls of tobacco designed for smoking. Cigars consist of filler leaves held together by binder leaves and covered with a wrapper leaf, which is rolled spirally around the ...

(Encyclopedia) aluminum ălˌyo͞omĭnˈēəm [key], metallic chemical element; symbol Al; at. no. 13; at. wt. 26.98154; m.p. 660.37℃; b.p. 2,467℃; sp. gr. 2.6989 at 20℃; valence +3. Aluminum is a silver-white...

(Encyclopedia) water pollution, contamination of water resources by harmful wastes; see also sewerage, water supply, pollution, and environmentalism. The United States has enacted extensive federal legislation to ...

(Encyclopedia)  CE5 Black mustard, Brassica nigra mustard, common name for the Cruciferae, or Brassicaceae, a large family chiefly of herbs of north temperate regions. The easily distinguished flowers of the Cruc...

(Encyclopedia) Houston, city (2020 pop. 2,304,580), seat of Harris co., SE Tex., a deepwater port on the Houston Ship Channel; inc. 1837. Harrisburg (now part of Hou...

(Encyclopedia) compound, in chemistry, a substance composed of atoms of two or more elements in chemical combination, occurring in a fixed, definite proportion and arranged in a fixed, definite structure. A compound...

(Encyclopedia) life, although there is no universal agreement as to a definition of life, its biological manifestations are generally considered to be organization, metabolism, growth, irritability, adaptation, and ...