Niobium
Electron Configuration: 2,8,18,12,1
Enthalpy of Fusion (kJ mol-1): 27.2
Enthalpy of Vaporisation (kJ mol-1): 680.19
Atomic Radii
Atomic Radius 145 pm
Bohr Radius 198 pm
Covalent Radius 137 pm
Van der Waals 0 pm
Oxidation States
Main Nb+5
Other Nb-3, Nb-1, Nb+1, Nb+2, Nb+3, Nb+4
Ionisation Energies (kJ mol-1) show graph
M - M+ 664
M+ - M2+ 1382
M2+ - M3+ 2416
M3+ - M4+ 3695
M4+ - M5+ 4877
M5+ - M6+ 9899
M6+ - M7+ 12100