Question

what is the oxidation number of gold metal

Answer 1

Melting point1337.33 K ​(1064.18 °C, ​1947.52 °F)Boiling point3243 K ​(2970 °C, ​5378 °F)Density (near r.t.)19.30 g/cm3when liquid (at m.p.)17.31 g/cm3Heat of fusion12.55 kJ/molHeat of vaporization342 kJ/molMolar heat capacity25.418 J/(mol·K)Vapor pressure

P (Pa)1101001 k10 k100 kat T (K)164618142021228126203078

Atomic propertiesOxidation states5, 3, 2, 1, −1, −2, −3 ​(an amphoteric oxide)ElectronegativityPauling scale: 2.54Ionization energies

1st: 890.1 kJ/mol

2nd: 1980 kJ/mol

Atomic radiusempirical: 144 pmCovalent radius136±6 pmVan der Waals radius166 pm



Spectral lines

Other propertiesCrystal structure​face-centered cubic (fcc)



Speed of soundthin rod2030 m/s (at r.t.)Thermal expansion14.2 µm/(m·K) (at 25 °C)Thermal conductivity318 W/(m·K)Electrical resistivity22.14 nΩ·m (at 20 °C)Magnetic orderingdiamagnetic[2]Magnetic susceptibility−28.0·10−6 cm3/mol (at 296 K)[3]Tensile strength120 MPaYoung's modulus79 GPaShear modulus27 GPaBulk modulus180 GPa[4]Poisson ratio0.4Mohs hardness2.5Vickers hardness188–216 MPaBrinell hardness188–245 MPaCAS Number7440-57-5HistoryNamingfrom Latin aurum, meaning goldDiscoveryIn the Middle East (before 6000 BCE)Main isotopes of goldIso­topeAbun­danceHalf-life(t1/2)Decay modePro­duct195Ausyn186.10 dε195Pt196Ausyn6.183 dε196Ptβ−196Hg197Au100%stable198Ausyn2.69517 dβ−198Hg199Ausyn3.169 dβ−199Hg