Iridium

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Iridium,  77Ir
Pieces o pure iridium
General properties
Appearance sillery white
Staundart atomic wecht (Ar, staundart) 192.217(3)
Iridium 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 Gold 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
Rh

Ir

Mt
osmiumiridiumplatinum
Atomic nummer (Z) 77
Group group 9
Period period 6
Block d-block
Electron confeeguration [Xe] 4f14 5d7 6s2
Electrons per shell
2, 8, 18, 32, 15, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 2739 K ​(2466 °C, ​4471 °F)
Bylin pynt 4701 K ​(4428 °C, ​8002 °F)
Density (near r.t.) 22.56 g/cm3
when liquid (at m.p.) 19 g/cm3
Heat o fusion 41.12 kJ/mol
Heat o vapourisation 563 kJ/mol
Molar heat capacity 25.10 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2713 2957 3252 3614 4069 4659
Atomic properties
Oxidation states −3,−1, 0, 1, 2, 3, 4, 5, 6, 8
Electronegativity Pauling scale: 2.20
Atomic radius empirical: 136 pm
Covalent radius 141±6 pm
Color lines in a spectral range
Miscellanea
Crestal structur face-centred cubic (fcc)
Face-centered cubic creestal structur for iridium
Speed o soond thin rod 4825 m/s (at 20 °C)
Thermal expansion 6.4 µm/(m·K)
Thermal conductivity 147 W/(m·K)
Electrical resistivity 47.1 n Ω·m (at 20 °C)
Magnetic orderin paramagnetic[1]
Young's modulus 528 GPa
Shear modulus 210 GPa
Bouk modulus 320 GPa
Poisson ratio 0.26
Mohs haurdness 6.5
Vickers haurdness 1760 MPa
Brinell haurdness 1670 MPa
CAS Nummer 7439-88-5
History
Diskivery Smithson Tennant (1803)
First isolation Smithson Tennant (1803)
Main isotopes o iridium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
188Ir syn 1.73 d ε 188Os
189Ir syn 13.2 d ε 189Os
190Ir syn 11.8 d ε 190Os
191Ir 37.3% - (α) 187Re
192Ir syn 73.827 d β 1.460 192Pt
ε 1.046 192Os
192m2Ir syn 241 y IT 192Ir
193Ir 62.7% - (α) 189Re
193mIr syn 10.5 d IT 193Ir
194Ir syn 19.3 h β 194Pt
194m2Ir syn 171 d IT 194Ir
Decay modes in parentheses are predictit, but hae nae yet been observed
| references | in Wikidata

Iridium is the chemical element wi seembol Ir an atomic nummer 77. A vera haurd, brickle, siller-white transeetion metal o the platinum faimily, iridium is the seicont-densest element (efter osmium) an is the maist corrosion-resistant metal, even at temperaturs as heich as 2000 °C. Tho anerly certaint molten sauts an halogens is corrosive tae solit iridium, finely dividit iridium dust is a fair bit mair reactive an can be flammable.

References[eedit | eedit soorce]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.