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oxidation and reduction

(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...

acids and bases

(Encyclopedia)acids and bases, two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Another theory that provides a very broad ...

permutations and combinations

(Encyclopedia)permutations and combinations: see probability. ...

orchestra and orchestration

(Encyclopedia)CE5 Typical seating plan of a symphony orchestra orchestra and orchestration, an orchestra is a musical ensemble of mixed instruments based on strings and winds, under the direction of a conductor...

visit and search

(Encyclopedia)visit and search: see search, right of. ...

Manuel I, Byzantine emperor

(Encyclopedia)Manuel I (Manuel Comnenus) kŏmnēˈnəs [key], c.1120–1180, Byzantine emperor (1143–80), son and successor of John II. He began his reign with a war against the Seljuk Turks, the subjugation of R...

Alfonso I, king of Portugal

(Encyclopedia)Alfonso I, 1109?–1185, first king of Portugal, son of Henry of Burgundy. After his father's death (1112), his mother, Countess Teresa, ruled the county of Portugal with the help of her Spanish lover...

Alfonso II, king of Portugal

(Encyclopedia)Alfonso II (Alfonso the Fat), 1185–1223, king of Portugal (1211–23), son and successor of Sancho I. His reign was spent in struggles with the church and his brothers and sisters, to whom his fathe...

Alfonso IV, king of Portugal

(Encyclopedia)Alfonso IV, 1291–1357, king of Portugal (1325–57), son and successor of Diniz. Disgruntled by the favoritism his father showed toward Alfonso's illegitimate half-brothers, Alfonso rose in revolt i...

Alfonso V, king of Portugal

(Encyclopedia)Alfonso V, 1432–81, king of Portugal (1438–81), son of Duarte and Queen Leonor. During his minority there was a struggle for the regency between the queen mother and Alfonso's uncle, Dom Pedro, du...