Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard and brittle transition ...ChromiumFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchChemicalelementwithatomicnumber24Thisarticleisaboutthechemicalelement.Forotheruses,seeChromium(disambiguation).Chemicalelementwithatomicnumber24Chromium, 24CrChromiumAppearancesilverymetallicStandardatomicweightAr, std(Cr)51.9961(6)[1]ChromiumintheperiodictableHydrogenHeliumLithiumBerylliumBoronCarbonNitrogenOxygenFluorineNeonSodiumMagnesiumAluminiumSiliconPhosphorusSulfurChlorineArgonPotassiumCalciumScandiumTitaniumVanadiumChromiumManganeseIronCobaltNickelCopperZincGalliumGermaniumArsenicSeleniumBromineKryptonRubidiumStrontiumYttriumZirconiumNiobiumMolybdenumTechnetiumRutheniumRhodiumPalladiumSilverCadmiumIndiumTinAntimonyTelluriumIodineXenonCaesiumBariumLanthanumCeriumPraseodymiumNeodymiumPromethiumSamariumEuropiumGadoliniumTerbiumDysprosiumHolmiumErbiumThuliumYtterbiumLutetiumHafniumTantalumTungstenRheniumOsmiumIridiumPlatinumGoldMercury(element)ThalliumLeadBismuthPoloniumAstatineRadonFranciumRadiumActiniumThoriumProtactiniumUraniumNeptuniumPlutoniumAmericiumCuriumBerkeliumCaliforniumEinsteiniumFermiumMendeleviumNobeliumLawrenciumRutherfordiumDubniumSeaborgiumBohriumHassiumMeitneriumDarmstadtiumRoentgeniumCoperniciumNihoniumFleroviumMoscoviumLivermoriumTennessineOganesson–↑Cr↓Movanadium←chromium→manganeseAtomicnumber(Z)24Groupgroup 6Periodperiod 4Block d-blockElectronconfiguration[Ar]3d54s1Electronspershell2,8,13,1PhysicalpropertiesPhaseat STPsolidMeltingpoint2180 K​(1907 °C,​3465 °F)Boilingpoint2944 K​(2671 °C,​4840 °F)Density(near r.t.)7.19 g/cm3when liquid(at m.p.)6.3 g/cm3Heatoffusion21.0 kJ/molHeatofvaporization347 kJ/molMolarheatcapacity23.35 J/(mol·K)Vapor pressureP (Pa)1101001 k10 k100 kat T (K)165618071991222325302942AtomicpropertiesOxidationstates−4,−2,−1,0,+1,+2,+3,+4,+5,+6(depending ontheoxidationstate,anacidic,basic