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terbium

(Encyclopedia)terbium tûrˈbēəm [key] [from Ytterby, a village in Sweden], metallic chemical element; symbol Tb; at. no. 65; at. wt. 158.92535; m.p. 1,356℃; b.p. 3,123℃; sp. gr. about 8.25; valence +3 or +4....

osmium

(Encyclopedia)osmium ŏzˈmēəm [key], metallic chemical element; symbol Os; at. no. 76; at. wt. 190.23; m.p. 3,045±30℃; b.p. 5,027±100℃; sp. gr. 22.57 at 20℃; valence usually +0 to +8. Osmium is a very ha...

etching

(Encyclopedia)etching, the art of engraving with acid on metal; also the print taken from the metal plate so engraved. In hard-ground etching the plate, usually of copper or zinc, is given a thin coating or ground ...

sodium

(Encyclopedia)sodium, a metallic chemical element; symbol Na [Lat. natrium]; at. no. 11; at. wt. 22.98977; m.p. 97.81℃; b.p. 892.9℃; sp. gr. 0.971 at 20℃; valence +1. Sodium is a soft, silver-white metal. Ext...

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...

Cîmpulung

(Encyclopedia)Cîmpulung kəmpo͝olo͞ongˈ [key], town, S central Romania, in Walachia, on the southern slope of the ...

cinnabar

(Encyclopedia)cinnabar sĭnˈəbär [key], mineral, the sulfide of mercury, HgS. Deep red in color, it is used as a pigment (see vermilion), but principally it is a source of the metal mercury. It is mined in Spain...

amalgamation process

(Encyclopedia)amalgamation process əmălˌgəmāˈshən [key], in particular, a method to extract gold and silver from ores. The ore is crushed and treated with mercury, in which the metal dissolves. The amalgam i...

Ambridge

(Encyclopedia)Ambridge, industrial borough (2020 pop. 6,513), Beaver co., W Pa., on the Ohio River; inc. 1905. Founded by and named for the American Bridge Co. in 1901, it now manufactures plastics, pro...

Amici, Giovanni Battista

(Encyclopedia)Amici, Giovanni Battista jōvänˈnē bät-tēsˈtä ämēˈchē [key], 1786–1863, Italian astronomer, mathematician, and naturalist. He became director of the observatory and professor of astronomy...