| Tecken | Nb |
| Atomnummer | 41 |
| Grupp | 5 (Vanadingruppen) |
| Period | 5 |
| Block | d |
| Ämnesklass | Övergångsmetall |
| Utseende | Gray metallic, bluish when oxidized |
| Färg | Grå |
| Antal protoner | 41 p+ |
| Antal neutroner | 52 n0 |
| Antal elektroner | 41 e- |
| Fas vid STP | Fast |
| Densitet | 8.57 g/cm3 |
| Relativ atommassa | 92.9064 u |
| Smältpunkt | 2750 K 2476.85 °C 4490.33 °F |
| Kokpunkt | 5017 K 4743.85 °C 8570.93 °F |
| Ångbildningsvärme | 690.1 kJ/mol |
| Elektronegativitet (Paulingskalan) | 1.6 |
| Elektronaffinitet | 88.516 kJ/mol |
| Oxidationstal | −3, −1, 0, +1, +2, +3, +4, +5 (a mildly acidic oxide) |
| Jonisationspotential |
|
| Upptäckt | Charles Hatchett (1801) |
| Första isolation | Christian Wilhelm Blomstrand (1864) |
| Recognized as a distinct element by | Heinrich Rose (1844) |
Upptäckten av niob Niobium was identified by English chemist Charles Hatchett in 1801. He found a new element in a mineral sample that had been sent to England from Connecticut, United States in 1734 by John Winthrop F.R.S. (grandson of John Winthrop the Younger) and named the mineral columbite and the new element columbium after Columbia, the poetic name for the United States. In 1809, English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. German chemist Heinrich Rose determined in 1846 that tantalum ores contain a second element, which he named niobium. In 1864 and 1865, a series of scientific findings clarified that niobium and columbium were the same element (as distinguished from tantalum), and for a century both names were used interchangeably. Niobium was officially adopted as the name of the element in 1949, but the name columbium remains in current use in metallurgy in the United States. | |