platinum ← gold → mercury | Ag ↑ Au ↓ Rg | |
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Appearance |
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metallic yellow
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General properties |
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Name, symbol, number | gold, Au, 79 |
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Pronunciation | |
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Element category | transition metal |
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Group, period, block | 11, 6, d |
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Standard atomic weight | 196.966569(4) |
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Electron configuration | [Xe] 4f14 5d10 6s1 |
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Electrons per shell | 2, 8, 18, 32, 18, 1 (Image) |
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Physical properties |
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Phase | solid |
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Density (near r.t.) | 19.30 g·cm−3 |
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Liquid density at m.p. | 17.31 g·cm−3 |
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Melting point | 1337.33 K, 1064.18 °C, 1947.52 °F |
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Boiling point | 3129 K, 2856 °C, 5173 °F |
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Heat of fusion | 12.55 kJ·mol−1 |
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Heat of vaporization | 324 kJ·mol−1 |
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Molar heat capacity | 25.418 J·mol−1·K−1 |
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Vapor pressure |
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P (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k | at T (K) | 1646 | 1814 | 2021 | 2281 | 2620 | 3078 |
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Atomic properties |
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Oxidation states | -1, 1, 2, 3, 4, 5 (amphoteric oxide) |
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Electronegativity | 2.54 (Pauling scale) |
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Ionization energies | 1st: 890.1 kJ·mol−1 |
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2nd: 1980 kJ·mol−1 |
Atomic radius | 144 pm |
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Covalent radius | 136±6 pm |
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Van der Waals radius | 166 pm |
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Miscellanea |
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Crystal structure | Lattice face centered cubic |
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Magnetic ordering | diamagnetic |
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Electrical resistivity | (20 °C) 22.14 nΩ·m |
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Thermal conductivity | 318 W·m−1·K−1 |
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Thermal expansion | (25 °C) 14.2 µm·m−1·K−1 |
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Speed of sound (thin rod) | (r.t.) 2030 m·s−1 |
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Tensile strength | 120 MPa |
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Young's modulus | 79 GPa |
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Shear modulus | 27 GPa |
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Bulk modulus | 180 GPa |
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Poisson ratio | 0.44 |
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Mohs hardness | 2.5 |
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Vickers hardness | 216 MPa |
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Brinell hardness | 25 HB MPa |
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CAS registry number | 7440-57-5 |
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Most stable isotopes |
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Main article: Isotopes of gold |
iso | NA | half-life | DM | DE (MeV) | DP |
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195Au | syn | 186.10 d | ε | 0.227 | 195Pt | 196Au | syn | 6.183 d | ε | 1.506 | 196Pt | β− | 0.686 | 196Hg | 197Au | 100% | 197Au is stable with 118 neutrons | 198Au | syn | 2.69517 d | β− | 1.372 | 198Hg | 199Au | syn | 3.169 d | β− | 0.453 | 199Hg |
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· r |