Niobium

Symbol | Nb
Latin name | Niobium
Atomic number | 41
Period | 5
Element category | Transition elements
Relative atomic mass | 92.90638
Group | V.B
Electronegativity | 1.6
Oxidation numbers | 3, 5
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1
Density [g/cm3] | 8.57
State | Solid
Melting point [°C] | 2468
Boiling point [°C] | 4742
Atomic radius [pm] | 198
Covalent radius [pm] | 137
Thermal conductivity [W m-1K-1] | 53.7
Heat capacity [J K-1g-1] | 0.265
Discovery | 1801
Hardness [Mohs scale] | 6.0
Vickers hardness [MPa] | 1320
Brinell hardness [MPa] | 736
Young's modulus [GPa] | 105
Electrical conductivity [S m-1] | 6.7 · 106
Shear modulus [GPa] | 38
1.st ionization energy [eV] | 6.7589
2.nd ionization energy [eV] | 14.32
3.rd ionization energy [eV] | 25.04
Stable isotopes | 1
Unstable isotopes | 21