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osmium

[oz-mee-uh m] /ˈɒz mi əm/
noun, Chemistry
1.
a hard, heavy, metallic element having the greatest density of the known elements and forming octavalent compounds, as OsO 4 and OsF 8 : used chiefly as a catalyst, in alloys, and in the manufacture of electric-light filaments. Symbol: Os; atomic weight: 190.2; atomic number: 76; specific gravity: 22.57.
Origin
1795-1805
1795-1805; < New Latin < Greek osm() smell + -ium -ium; named from the penetrating odor of one of its oxides
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Based on the Random House Dictionary, © Random House, Inc. 2014.
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Examples from the web for osmium
  • Two elements sometimes found inside gold, rhenium and osmium, help serve as a radioactive clock.
British Dictionary definitions for osmium

osmium

/ˈɒzmɪəm/
noun
1.
a very hard brittle bluish-white metal occurring with platinum and alloyed with iridium in osmiridium: used to produce platinum alloys, mainly for pen tips and instrument pivots, as a catalyst, and in electric-light filaments. Symbol: Os; atomic no: 76; atomic wt: 190.2; valency: 0 to 8; relative density: 22.57; melting pt: 3033±30°C; boiling pt: 5012±100°C
Word Origin
C19: from Greek osmē smell, so called from its penetrating odour
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for osmium
n.

metallic element, 1803, coined in Modern Latin by its discoverer, English chemist Smithson Tennant (1761-1815) from Greek osme "smell, scent, odor" good or bad (cognate with Latin odor; see odor). So called for the strong smell of its oxide.

Online Etymology Dictionary, © 2010 Douglas Harper
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osmium in Medicine

osmium os·mi·um (ŏz'mē-əm)
n.
Symbol Os
A hard metallic element, found in small amounts in osmiridium and platinum ores. Atomic number 76; atomic weight 190.2; melting point 3,000°C; boiling point 5,000°C; specific gravity 22.57; valence 3, 4, 6, 8.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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osmium in Science
osmium
  (ŏz'mē-əm)   
Symbol Os
A hard, brittle, bluish-white metallic element that is the densest naturally occurring element. It is used to make very hard alloys for fountain pen points, electrical contacts, and instrument pivots. Atomic number 76; atomic weight 190.2; melting point 3,000°C; boiling point 5,000°C; specific gravity 22.57; valence 2, 3, 4, 8. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Article for osmium

Os

(Os), chemical element, one of the platinum metals of Group VIIIb of the periodic table and the densest naturally occurring element. A gray-white metal, osmium is very hard, brittle, and difficult to work, even at high temperatures. Of the platinum metals it has the highest melting point, so fusing and casting are difficult. Osmium wires were used for filaments of early incandescent lamps before the introduction of tungsten. It has been used chiefly as a hardener in alloys of the platinum metals, though ruthenium has generally replaced it. A hard alloy of osmium and iridium has been used for tips of fountain pens and phonograph needles, and osmium tetroxide is used in certain organic syntheses.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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