Cobalt (Co)

From Wikipedia, the free encyclopediaCobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

Cobalt in the periodic table

SymbolCo
Atomic number27
Group9
Period4
Blockd
Element categoryTransition Metal

Physical properties

Phase at STPSolid
Density8.9 g/cm3
Atomic weight58.9332 u
Melting point1768 K
1494.85 °C
2722.73 °F
Boiling point3200 K
2926.85 °C
5300.33 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.88
Electron affinity63.898 kJ/mol
Ionization energies
1760.4 kJ/mol
2 1648 kJ/mol
3 3232 kJ/mol
4 4950 kJ/mol
5 7670 kJ/mol
6 9840 kJ/mol
7 12440 kJ/mol
8 15230 kJ/mol
9 17959 kJ/mol
10 26570 kJ/mol
11 29400 kJ/mol
12 32400 kJ/mol
13 36600 kJ/mol
14 39700 kJ/mol
15 42800 kJ/mol
16 49396 kJ/mol
17 52737 kJ/mol
18 134810 kJ/mol
19 145170 kJ/mol
20 154700 kJ/mol
21 167400 kJ/mol
22 178100 kJ/mol
23 189300 kJ/mol
24 204500 kJ/mol
25 214100 kJ/mol
26 920870 kJ/mol
27 966023 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d7 4s2
Electrons per shell2, 8, 15, 2

History

Discovered1735
Discovered byGeorg Brandt