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forging

(Encyclopedia)forging, shaping metal by heating it and then hammering or rolling it. Forging is the method by which metal was first worked when it came into use about 4000 b.c. in Egypt and Asia. Modern forging is ...

zirconium

(Encyclopedia)zirconium zərkōˈnēəm [key], metallic chemical element; symbol Zr; at. no. 40; at. wt. 91.224; m.p. about 1,852℃; b.p. 4,377℃; sp. gr. 6.5 at 20℃; valence +2, +3, or +4. Zirconium is a very ...

metallic bond

(Encyclopedia)metallic bond: see chemical bond; metal. ...

metallurgy

(Encyclopedia)metallurgy mĕtˈəlûrˌjē [key], science and technology of metals and their alloys. Modern metallurgical research is concerned with the preparation of radioactive metals, with obtaining metals econ...

jew's-harp

(Encyclopedia)jew's-harp or jews'-harp, musical instrument of ancient lineage composed of a small metal frame containing a flexible metal tongue. The frame is held between the teeth and the metal tongue is plucked ...

hydrogen sulfide

(Encyclopedia)hydrogen sulfide, chemical compound, H2S, a colorless, extremely poisonous gas that has a very disagreeable odor, much like that of rotten eggs. It is slightly soluble in water and is soluble in carbo...

assaying

(Encyclopedia)assaying əsāˈyĭng, ăsˈāyĭng [key], in metallurgy, process of determining the specific metallic content of an ore, alloy, or other substance, especially one containing precious metals. It consi...

peroxide

(Encyclopedia)peroxide pərŏkˈsīd [key], chemical compound containing two oxygen atoms, each of which is bonded to the other and to a radical or some element other than oxygen; e.g., in hydrogen peroxide, H2O2, ...

electroscope

(Encyclopedia)electroscope, device for detecting electric charge invented by Nollet in 1748. There are various types of electroscopes. The most common has a cylindrical metal case closed by two round, flat, glass f...

caustic

(Encyclopedia)caustic, any strongly corrosive chemical substance, especially one that attacks organic matter. A caustic alkali is a metal hydroxide, especially that of an alkali metal; caustic soda is sodium hydrox...