Chemical properties of Niobium

• Atomic number:
• 41

• Atomic mass:
• 92.906 g.mol ^-1

• Electronegativity according to Pauling:
• 1.6

• Density:
• 8.57 g.cm^-3 at 20°C

• Melting point:
• 2477 °C

• Boiling point:
• 4744 °C

• Vanderwaals radius:
• 0.164 nm

• Ionic radius:
• 0.146

• Isotopes:
• 2

• Electronic shell:
• [ Kr ] 4d⁴ 5s¹

• Energy of first ionisation:
• 652.1 kJ.mol ^-1

Niobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41. It is a soft, grey, ductiletransition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite. The name comes from Greek mythology: Niobe, daughter of Tantalus since it is so similar to tantalum.
Applications
Niobium in the environment After the separation from the other minerals, the mixed oxides of tantalum Ta2O5 and niobium Nb2O5 are obtained. The first step in the processing is the reaction of the oxides with hydrofluoric acid. Niobium-containing compounds are rarely encountered by most people, but some are toxic and should be treated with care. .