Atomic number 41 · Transition metal
Niobium Nb
Niobium is a soft, grey, lustrous transition metal. A tiny addition to steel makes it much stronger and tougher, so it ends up in pipelines, car bodies and bridges. It also becomes superconducting at a higher temperature than any other element at normal pressure, which makes it indispensable for MRI scanners and particle accelerators.
Key properties
| Atomic number | 41 |
|---|---|
| Atomic weight | 92.906 (CIAAW 2024 abridged standard atomic weight) |
| Category | Transition metal |
| Group | 5 |
| Period | 5 |
| Block | d |
| State (25 °C, 1 atm) | Solid |
| Melting point | 2750 K (2476.8 °C) |
| Boiling point | 5017 K (4743.9 °C) |
| Density | 8.57 g/cm³ |
| Electronegativity (Pauling) | 1.6 |
| Atomic radius (van der Waals) | 207 pm |
| First ionization energy | 6.759 eV |
| Electron affinity | 0.893 eV |
| Oxidation states | +5, +3 |
| Discovered | 1801 |
Electron configuration
- Condensed
- [Kr]5s1 4d4
- Full
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1
- Electrons per shell
- 2 · 8 · 18 · 12 · 1
Orbital diagram
Position in the table
Discovery
In 1801 the English chemist Charles Hatchett analysed a mineral specimen that had come from North America and announced a new element, which he called columbium.
A year later tantalum was discovered in Sweden, and the two were so alike that in 1809 William Hyde Wollaston concluded they were the same element. The confusion lasted until 1844, when the German chemist Heinrich Rose demonstrated that there were two distinct elements and gave this one a new name, niobium.
Christian Wilhelm Blomstrand first prepared the metal in 1864. For about a century European chemists said niobium while American metallurgists kept saying columbium, until the International Union of Pure and Applied Chemistry adopted niobium as the official name in 1949.
Origin of the name
In Greek mythology Niobe is the daughter of Tantalus. Rose chose the name to reflect the element's inseparable relationship with tantalum. The symbol is Nb.
Main uses
- High-strength low-alloy steel: adding around 0.1% niobium refines the grain structure, giving strong, tough steel for pipelines, car bodies, bridges and building frames. This accounts for most niobium consumption.
- Superalloys: niobium improves the high-temperature strength of jet and rocket engine parts.
- Superconducting magnets: niobium–titanium wire forms the magnets of hospital MRI machines and the Large Hadron Collider, while niobium–tin is used where even stronger fields are needed. Pure niobium is shaped into superconducting radio-frequency cavities for accelerators.
- Jewellery: niobium rarely causes allergies and can be anodised to a range of vivid colours.
Isotopes
Niobium has a single stable isotope, niobium-93. Radioactive niobium-95, with a half-life of about 35 days, is a fission product measured in environmental monitoring around nuclear facilities, and niobium-94 is a long-lived activation product with a half-life of tens of thousands of years.
In everyday life
Niobium is extracted from pyrochlore and columbite ores. Supply is extremely concentrated: roughly 90% of the world's niobium comes from Brazil, above all from a mine near Araxá in Minas Gerais.
It is hidden in the steel of cars and buildings and in the magnets of hospital MRI scanners. Because the metal is biologically inert, it is used for body jewellery and some medical implants.
Good to know
- Niobium superconducts below about 9.2 K, the highest transition temperature of any element at normal pressure.
- Like the mythical father and daughter, tantalum and niobium almost always occur together in ores.
- Anodised niobium shows blue, purple or gold depending on the thickness of its oxide layer.
Same group (5)
Data sources · Properties: PubChem Periodic Table (US NIH/NLM public data) · Atomic weights: CIAAW 2024 abridged standard atomic weights · Names: Wikidata (CC0); Korean names follow the Korean Chemical Society. Retrieved 2026-09-23.