Alkali Metal

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alkali metal

[′al·kə‚lī ‚med·əl]
(chemistry)
Any of the elements of group I in the periodic table: lithium, sodium, potassium, rubidium, cesium, and francium.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Alkali Metal

 

any one of several chemical elements of the major subgroup of Group I of Mendeleev’s periodic system of the elements: lithium, sodium, potassium, rubidium, cesium, and francium. The subgroup’s name is derived from the hydroxides of the alkali metals, called caustic alkalies. The atoms of alkali metals have one s electron in their outer shell and, with the exception of lithium, two 5 electrons and six p electrons in the next to the last shell. The alkali metals always exhibit an oxidation number of +1 in their compounds. They are very reactive chemically. They are oxidized rapidly by atmospheric oxygen and react vigorously with water to form alkalies, MeOH (where Me is a metal). Their reactivity increases from lithium to francium. (See alsoLITHIUM; SODIUM; POTASSIUM; RUBIDIUM; CESIUM; and FRANCIUM.)

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.