Osmium

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Osmium,  76Os
Osmium crystals.jpg
General properties
Appearance sillery, blue cast
Staundart atomic wecht (Ar, staundart) 190.23(3)[1]
Osmium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Ru

Os

Hs
rheniumosmiumiridium
Atomic nummer (Z) 76
Group group 8
Period period 6
Element category   transition metal
Block d-block
Electron confeeguration [Xe] 4f14 5d6 6s2
Electrons per shell
2, 8, 18, 32, 14, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 3306 K ​(3033 °C, ​5491 °F)
Bylin pynt 5285 K ​(5012 °C, ​9054 °F)
Density (near r.t.) 22.59 g/cm3
when liquid (at m.p.) 20 g/cm3
Heat o fusion 57.85 kJ/mol
Heat o vapourisation 738 kJ/mol
Molar heat capacity 24.7 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 3160 3423 3751 4148 4638 5256
Atomic properties
Oxidation states 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2
(mildly acidic oxide)
Electronegativity Pauling scale: 2.2
Atomic radius empirical: 135 pm
Covalent radius 144±4 pm
Coloyr lines in a spectral range
Spectral lines o Osmium
Miscellanea
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for osmium
Speed o soond thin rod 4940 m/s (at 20 °C)
Thermal expansion 5.1 µm/(m·K) (at 25 °C)
Thermal conductivity 87.6 W/(m·K)
Electrical resistivity 81.2 n Ω·m (at 0 °C)
Magnetic orderin paramagnetic[2]
Shear modulus 222 GPa
Bouk modulus 462 GPa
Poisson ratio 0.25
Mohs haurdness 7.0
Brinell haurdness 3920 MPa
CAS Nummer 7440-04-2
History
Diskivery Smithson Tennant (1803)
First isolation Smithson Tennant (1803)
Main isotopes o osmium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
184Os 0.02% >5.6×1013 y (β+β+) 184W
(α) 180W
185Os syn 93.6 d ε 185Re
186Os 1.59% 2.0×1015 y α 182W
187Os 1.96% - (α) 183W
188Os 13.24% - (α) 184W
189Os 16.15% - (α) 185W
190Os 26.26% - (α) 186W
191Os syn 15.4 d β 191Ir
192Os 40.78% >9.8×1012 y (ββ) 192Pt
(α) 188W
193Os syn 30.11 d β 193Ir
194Os syn 6 y β 194Ir
Decay modes in parentheses are predictit, but hae nae yet been observed
| references | in Wikidata

Osmium (frae Greek osme (ὀσμή) meanin "smell") is a chemical element wi the seembol Os an atomic nummer 76. It is a haird, brickle, blaeish-white transeetion metal in the platinum faimily an is the densest naiturally occurrin element, wi a density o 22.59 g/cm3. It is foond as a trace element in alloys, maistly in platinum ores. Its alloys wi platinum, iridium, an ither platinum group metals are employed in fountain pen tips, electrical contacts, an ither applications whaur extreme durability an hairdness are needit.[3]

References[eedit | eedit soorce]

  1. Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305. 
  2. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
  3. Hammond "Osmium", C. R., p. 4–25 in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.