Element Properties
By Name
By Atomic Number
By Density
Melting & Boiling Point
Electron Configuration
Radioactive Elements
Noble & Precious Metals
Periodic Table
Groups
Periodic Table
Alkali Metals
Alkaline Earth Metals
Halogens
Noble (Inert) Gases
Rare Earth Elements
Transition Metals
Metalloids (Semimetals)
Nonmetals
Poor Metals
Materials
Toxic Substances
Semiconductor Materials
Vitamins
Amino Acids
Inventions
& Patents
Reference
|
Cobalt
Chemical Properties & Compounds
| Symbol | Atomic Number | Atomic Weight | Melting Point | Boiling Point | Phase | Density | Classification |
| Co | 27 | 58.933195 | 1495 °C | 2927 °C | Solid | 8.90 g/cm3 | Metal  |
|
|
|
| General |
| Name, symbol, number |
cobalt, Co, 27 |
| Chemical series |
transition metals |
| Group, period, block |
9, 4, d |
| Appearance |
metallic with gray tinge
 |
| Standard atomic weight |
58.933195(5) g·mol−1 |
| Electron configuration |
[Ar] 3d7 4s2 |
| Electrons per shell |
2, 8, 15, 2 |
| Density (near r.t.) |
8.90 g·cm−3 |
| Liquid density at m.p. |
7.75 g·cm−3 |
| Melting point |
1768 K
(1495 °C, 2723 °F) |
| Boiling point |
3200 K
(2927 °C, 5301 °F) |
| Heat of fusion |
16.06 kJ·mol−1 |
| Heat of vaporization |
377 kJ·mol−1 |
| Heat capacity |
(25 °C) 24.81 J·mol−1·K−1 |
Vapor pressure
| P/Pa |
1 |
10 |
100 |
1 k |
10 k |
100 k |
| at T/K |
1790 |
1960 |
2165 |
2423 |
2755 |
3198 |
|
| Atomic properties |
| Crystal structure |
hexagonal |
| Oxidation states |
2, 3
(amphoteric oxide) |
| Electronegativity |
1.88 (Pauling scale) |
Ionization energies
(more) |
1st: 760.4 kJ·mol−1 |
| 2nd: 1648 kJ·mol−1 |
| 3rd: 3232 kJ·mol−1 |
| Atomic radius |
135 pm |
| Atomic radius (calc.) |
152 pm |
| Covalent radius |
126 pm |
| Miscellaneous |
| Magnetic ordering |
ferromagnetic |
| Electrical resistivity |
(20 °C) 62.4 nΩ·m |
| Thermal conductivity |
(300 K) 100 W·m−1·K−1 |
| Thermal expansion |
(25 °C) 13.0 µm·m−1·K−1 |
| Speed of sound (thin rod) |
(20 °C) 4720 m/s |
| Young's modulus |
209 GPa |
| Shear modulus |
75 GPa |
| Bulk modulus |
180 GPa |
| Poisson ratio |
0.31 |
| Mohs hardness |
5.0 |
| Vickers hardness |
1043 MPa |
| Brinell hardness |
700 MPa |
| CAS registry number |
7440-48-4 |
| Selected isotopes |
|
|
| References |
|
Cobalt Compounds
|
Source: Wikipedia article Cobalt
|
|
Chemistry Quick Facts
