Cobalt was first discovered by Georg Brandt, a Swedish chemist, in 1735.
Name: Cobalt
Symbol: Co
Atomic number: 27
Atomic weight: 58.933
State: solid
Group, period, block: 9, 4, d
Color: hard lustrous gray metal
Classification: transition metal
Electron configuration: 4s2 3d7
2,8,15,2
Physical properties
Density: 8.90 g/cm-3
Melting point: 1768 K, 1495 °C, 2723 °F
Boiling point: 3200 K, 2927 °C, 5301 °F
Atomic properties
Oxidation states: 5, 4, 3, 2, 1, -1[2]
Electronegativity: 1.88 (Pauling scale)
Ionization energies: 1st: 760.4 kJ·mol-1
Covalent radius: 126±3 (low spin), 150±7 (high spin) pm
Van der Waals radius: no data
- Co
Electron Configuration
Isotopes
There is only one naturally occurring isotope of cobalt exists, 59Co.