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gout

(Encyclopedia)gout, condition that manifests itself as recurrent attacks of acute arthritis, which may become chronic and deforming. It results from deposits of uric acid crystals in connective tissue or joints. Th...

hydroxide

(Encyclopedia)hydroxide hīdrŏkˈsīd [key], chemical compound that contains the hydroxyl (−OH) radical. The term refers especially to inorganic compounds. Organic compounds that have the hydroxyl radical as a f...

feldspar

(Encyclopedia)feldspar fĕlˈspär [key], an abundant group of rock-forming minerals which constitute 60% of the earth's crust. Chemically the feldspars are silicates of aluminum, containing sodium, potassium, iron...

sulfonic acid

(Encyclopedia)sulfonic acid səlfŏnˈĭk [key], organic compound containing the functional group RSO2OH, which consists of a sulfur atom, S, bonded to a carbon atom that may be part of a large aliphatic or aromati...

fire fighting

(Encyclopedia)fire fighting, the use of strategy, personnel, and apparatus to extinguish, to confine, or to escape from fire. Ancient Rome is known to have had a fire department consisting by the 1st cent. of app...

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...

strontium

(Encyclopedia)strontium strŏnˈshēəm [key] [from Strontian, a Scottish town], a metallic chemical element; symbol Sr; at. no. 38; at. wt. 87.62; m.p. 769℃; b.p. 1,384℃; sp. gr. 2.6 at 20℃; valence +2. Stro...

tungsten

(Encyclopedia)tungsten tŭngˈstən [key] [Swed.,=heavy stone], metallic chemical element; symbol W; at. no. 74; at. wt. 183.84; m.p. about 3,410℃; b.p. 5,660℃; sp. gr. 19.3 at 20℃; valence +2, +3, +4, +5, or...

mercury poisoning

(Encyclopedia)mercury poisoning, tissue damage resulting from exposure to more than trace amounts of the element mercury or its compounds. Elemental mercury (the silver liquid familiar from thermometers) is the mos...

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...