PERIODIC ELEMENT
Co (Cobalt)




Atomic number : 27
Atomic mass : 58.9332 g.mol-1
Electronegativity according to Pauling : 1.8
Density : 8.9 g.cm-3 at 20 °C
Melting point : 1495 °C
Boiling point : 2927 °C
Vanderwaals radius : 0.125 nm
Ionic radius : 0.078 (+2) nm ; 0.063 (+3) nm
Isotopes : 8
Electronic shell : [Ar] 3d7 4s2
Energy of first ionisation : 757 kJ.mol-1
Energy of second ionisation : 1666.3 kJ.mol-1
Energy of third ionisation : 3226 kJ.mol-1
Standard Potential : - 0.28 V (Co2+ / Co) ; + 1.84 V (Co3+ / Co2+)
Discovered by : George Brandt in 1737
 
Atomic Structure Uses (magnets, ceramics, special glasses)