osmium

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osmium (symbol Os) Bluish-white, metallic element, one of the transition elements. The densest of the elements, it is associated with platinum; the chief source is as a by-product from smelting nickel. Osmium is used in producing hard alloys and to make electrical contacts and pen points. It was discovered in 1804 by English chemist Smithson Tennant (1761–1815) who named it. Properties: at.no. 76; r.a.m. 190.2; r.d. 22.57; m.p. 3045°C (5513°F); b.p. 5027°C (9081 °F); most common isotope Os192 (41.0%).

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