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copper, chemical element

(Encyclopedia)copper, metallic chemical element; symbol Cu [Lat. cuprum=copper]; at. no. 29; at. wt. 63.546; m.p. 1,083.4℃; b.p. 2,567℃; sp. gr. 8.96 at 20℃; valence +1 or +2. Copper and some of its alloys ha...

mining

(Encyclopedia)mining, extraction of solid mineral resources from the earth. These resources include ores, which contain commercially valuable amounts of metals, such as iron and aluminum; precious stones, such as d...

artificial limb

(Encyclopedia)artificial limb, mechanical replacement for a missing limb. An artificial limb, called a prosthesis, must be light and flexible to permit easy movement, but must also be sufficiently sturdy to support...

statistical mechanics

(Encyclopedia)statistical mechanics, quantitative study of systems consisting of a large number of interacting elements, such as the atoms or molecules of a solid, liquid, or gas, or the individual quanta of light ...

Tasmania

(Encyclopedia)Tasmania tăzmāˈnēə [key], island state (2016 pop. 509,965), 26,383 sq mi (68,332 sq km), SE Commonwealth of Australia. It is separated from Australia by the Bass Strait and lies 150 mi (240 km) s...

complex ion

(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...

concentration

(Encyclopedia)concentration, in chemistry, measure of the relative proportions of two or more quantities in a mixture. The concentration of a solute is very important in studying chemical reactions because it deter...

Albany, cities, United States

(Encyclopedia)Albany 1, 3, 4 ôlˈbənē; 2 ôlˈbĕnˌē, ălbāˈnē [key]. 1 Residential city (2020 pop. 20,271), Alameda co., W Calif., on the eastern shore of San Francisco...

Champagne, historic region and former province, France

(Encyclopedia)Champagne shäNpäˈnyə [key], historic region and former province, NE France, consisting mainly of Aube, Marne, Haute-Marne, and Ardennes depts., which formed the modern administrative region of Cha...

iodine

(Encyclopedia)iodine īˈədīn, –dĭn [key] [Gr.,=violet], nonmetallic chemical element; symbol I; at. no. 53; at. wt. 126.90447; m.p. 113.5℃; b.p. 184.35℃; sp. gr. 4.93 at 20℃; valence −1, +1, +3, +5, o...