Niobium
Elemental State Nb
Electron Configuration 1s22s22p63s23p63d104s24p65s14d4
First Ionization Potential 6.759 eV
Electron Affinity 0.893 eV
Z*  
Pauling Electronegativity 1.6
Covalent Radius 1.37 Å
Metallic Radius 1.47 Å
Ionic Radius 0.86 Å Nb3+ coordination number = 6

0.82 Å Nb4+ coordination number = 6

0.62 Å Nb5+ coordination number = 4

0.78 Å Nb5+ coordination number = 6

0.88 Å Nb5+ coordination number = 8

van der Waal's Radius  
Melting Point 2477 oC
Boiling Point 4744 oC
Density 8.57 g/cm3
Other Properties