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