76Os190.23

Osmium (Os) – element 76

Osmium is a chemical element with the symbol Os and atomic number 76. It is a transition metal in group 8, period 6 of the periodic table (d-block), and is a solid at room temperature.

Osmium (Os) has atomic number 76, atomic mass 190.23 u and electron configuration [Xe] 4f14 5d6 6s2.

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Osmium facts

SymbolOs
Atomic number76
Atomic mass190.23 u (g/mol)
Categorytransition metal
Groupgroup 8
Period6
Blockd-block
Phase at 20 °CSolid
Electron configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d6
Noble-gas notation[Xe] 4f14 5d6 6s2
Electrons per shell2, 8, 18, 32, 14, 2

Bohr model and shells

Os

Osmium has 76 electrons in 6 shells: 2, 8, 18, 32, 14, 2. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.

Physical and atomic properties

Melting point3306 K (3032.8 °C)
Boiling point5285 K (5011.9 °C)
Density22.59 g/cm³
Electronegativity (Pauling)2.2
Electron affinity103.99 kJ/mol
Ionization energies840, 1600 kJ/mol (1st, 2nd)
Molar heat capacity24.7 J/(mol·K)
Discovered bySmithson Tennant

Use the atomic mass in the molar mass calculator for any formula containing Os.

Position in the periodic table

HydrogenHHeliumHeLithiumLiBerylliumBeBoronBCarbonCNitrogenNOxygenOFluorineFNeonNeSodiumNaMagnesiumMgAluminiumAlSiliconSiPhosphorusPSulfurSChlorineClArgonArPotassiumKCalciumCaScandiumScTitaniumTiVanadiumVChromiumCrManganeseMnIronFeCobaltCoNickelNiCopperCuZincZnGalliumGaGermaniumGeArsenicAsSeleniumSeBromineBrKryptonKrRubidiumRbStrontiumSrYttriumYZirconiumZrNiobiumNbMolybdenumMoTechnetiumTcRutheniumRuRhodiumRhPalladiumPdSilverAgCadmiumCdIndiumInTinSnAntimonySbTelluriumTeIodineIXenonXeCesiumCsBariumBaLanthanumLaCeriumCePraseodymiumPrNeodymiumNdPromethiumPmSamariumSmEuropiumEuGadoliniumGdTerbiumTbDysprosiumDyHolmiumHoErbiumErThuliumTmYtterbiumYbLutetiumLuHafniumHfTantalumTaTungstenWRheniumReOsmiumOsIridiumIrPlatinumPtGoldAuMercuryHgThalliumTlLeadPbBismuthBiPoloniumPoAstatineAtRadonRnFranciumFrRadiumRaActiniumAcThoriumThProtactiniumPaUraniumUNeptuniumNpPlutoniumPuAmericiumAmCuriumCmBerkeliumBkCaliforniumCfEinsteiniumEsFermiumFmMendeleviumMdNobeliumNoLawrenciumLrRutherfordiumRfDubniumDbSeaborgiumSgBohriumBhHassiumHsMeitneriumMtDarmstadtiumDsRoentgeniumRgCoperniciumCnNihoniumNhFleroviumFlMoscoviumMcLivermoriumLvTennessineTsOganessonOg

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Frequently asked questions

What is the atomic mass of osmium?

The atomic mass of osmium is 190.23 u, so one mole of osmium atoms weighs 190.23 g.

What is the electron configuration of osmium?

Osmium has 76 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁶, or [Xe] 4f¹⁴ 5d⁶ 6s² in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 14, 2.

Is osmium a metal?

Yes. Osmium is a transition metal.

Where is osmium on the periodic table?

Osmium is in group 8, period 6, in the d-block.

Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.