Columbia Encyclopedia

(Encyclopedia) complex ion, charged molecular aggregate (see ion), consisting of a metallic atom or ion to which is attached one or more electron-donating molecules. In some complex ions, such as sulfate, SO4−2, t...

(Encyclopedia) condensate, matter in the form of a gas of atoms, molecules, or elementary particles that have been so chilled that their motion is virtually halted and as a consequence they lose their separate ident...

(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...

(Encyclopedia)  CE5 A. Water molecule (black circles represent valence-shell electrons) B. Structure of ice: Each oxygen atom (white circles) is bonded to four other oxygen atoms by hydrogen bonds, the hydrogen at...

(Encyclopedia) Athanasius, Saint ăthənāˈzhəs [key], c.297–373, patriarch of Alexandria (328–73), Doctor of the Church, great champion of orthodoxy during the Arian crisis of the 4th cent. (see Arianism). In...

(Encyclopedia) oxidation and reduction, complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation was used to re...

(Encyclopedia) Vatican Council, Second, popularly called Vatican II, 1962–65, the 21st ecumenical council (see council, ecumenical) of the Roman Catholic Church, convened by Pope John XXIII and continued under Pau...

(Encyclopedia) Booker Prize, an award of £50,000 (originally £5,000) for the best novel of the year published in English in Great Britain; prior to 2014, it was only given to a British, Irish, or Commonwealth writ...

(Encyclopedia) Hawthorne, Nathaniel, 1804–64, American novelist and short-story writer, b. Salem, Mass., one of the great masters of American fiction. His novels and tales are penetrating explorations of moral and...

(Encyclopedia) quantum electrodynamics (QED), quantum field theory that describes the properties of electromagnetic radiation and its interaction with electrically charged matter in the framework of quantum theory. ...