79
Au
Gold
197
Gold (Au)
Transition MetalGroup 11Period 6d-block-block
Gold is a chemical element with symbol Au (from Latin:aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal. Chemically, gold is a transition metal and a group 11 element.
Latin name: Aurum
Atomic Number
79
Atomic Mass
197 g/mol
Phase (STP)
Solid
Electron Config.
[Xe] 4f¹⁴ 5d¹⁰ 6s¹
General
SymbolAu
Atomic Number79
Atomic Mass197 g/mol
CategoryTransition Metal
Group11
Period6
Blockd-block
Electron Configuration[Xe] 4f¹⁴ 5d¹⁰ 6s¹
Valence Electrons11
Colourlustrous golden-yellow metallic
Appearancemetallic yellow
CAS NumberCAS7440-57-5
Physical Properties
Phase (STP)Solid
Density19.32 g/cm³
Melting Point1064.18°C · 1947.52°F · 1337.33 K
Boiling Point2855.85°C · 5172.53°F · 3129.00 K
Atomic Properties
Atomic Radius166 pm
Electronegativity2.54 Pauling
Ionization Energy890 kJ/mol
Oxidation States+1, +3
Ion ChargeAu+/Au3+
Thermodynamic
Molar Heat25.418 J/(mol·K)
Crystal Structure
Crystal Structureface-centered cubic
Mechanical Properties
Mohs Hardness2.5
Nuclear & Hazards
Half-lifestable
Abundance
In Universe0.000004%
In Sun0.000003%
In Earth's Crust0.0000004%
In Oceans0.00000005%
In Meteorites0.00001%
Discovery & History
Discovered Byunknown
Isotopes of Gold
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Au-197 | 100% | Stable | — |