SymbolAu
Latin nameAurum
Atomic number79
Period6
Element categoryTransition elements
Relative atomic mass196.96654
GroupI.B
Electronegativity
2.4
Oxidation numbers
1, 3
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s1
Density [g/cm3]
19.32
State
Solid
Melting point [°C]
1064.43
Boiling point [°C]
2966
Atomic radius [pm]
174
Covalent radius [pm]
144
Thermal conductivity [W m-1K-1]
317
Heat capacity [J K-1g-1]
0.128
Discovery
Antiquity
Hardness [Mohs scale]
2.5
Vickers hardness [MPa]
216
Brinell hardness [MPa]
2450
Young's modulus [GPa]
78
Electrical conductivity [S m-1]
4.5 · 107
Electrical resistivity [10-6Ω.m]
0.022
Shear modulus [GPa]
27
1.st ionization energy [eV]
9.2257
2.nd ionization energy [eV]
20.521
Stable isotopes
1
Unstable isotopes
20