Niobium (Nb)
Element 41 · Transition metal · atomic mass 92.906 u · group 5, period 5
Electron shells: 2, 8, 18, 12, 1
Niobium is a soft, ductile metal that becomes superconducting when cold, and it is the alloy of choice for MRI and particle-accelerator magnets. Tiny additions also toughen pipeline steel.
The Large Hadron Collider's magnets are wound with niobium-titanium wire.
- Atomic number
- 41
- Atomic mass
- 92.906 u
- Electron configuration
- [Kr] 5s¹ 4d⁴
- Group · period · block
- 5 · 5 · d
- Oxidation states
- +3, +5
- Electronegativity
- 1.6 (Pauling)
- Melting point
- 2,477 °C
- Boiling point
- 4,744 °C
- Density
- 8.57 g/cm³
- State at 20 °C
- Solid
- Appearance
- Grey, lustrous metal
- Discovered
- Charles Hatchett, 1801
41 protons, and 41 electrons when neutral
IUPAC standard atomic weight
Vanadium group
What Niobium is used for
- Superconducting magnets in MRI and the LHC
- High-strength low-alloy steels
- Jet-engine superalloys
- Hypoallergenic jewellery
Atomic structure of Niobium
A neutral niobium atom has 41 protons and 41 electrons. Its most common isotope carries about 52 neutrons, which is where the mass number 93 comes from. Change the neutron count and you have a different isotope of niobium; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 18, 12, 1. In orbital notation that is [Kr] 5s¹ 4d⁴. As a d-block element its valence count is variable, which is why it can form compounds in several oxidation states.
3D electron orbitals
See where Niobium's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Niobium sits in the periodic table
The d-block. Multiple stable oxidation states give them coloured compounds, catalytic ability and the strength that makes them the working metals of industry.
- Directly above: Vanadium — same group, so similar chemistry with a smaller atom.
- Directly below: Tantalum — same group, one shell larger.
- One proton lighter: Zirconium.
- One proton heavier: Molybdenum.
Discovery and naming
Niobium was discovered by Charles Hatchett in 1801. Its name comes from Niobe, daughter of Tantalus in Greek myth, which is also why its symbol (Nb) does not match its English name.
Keep exploring
Atomic weight from IUPAC/CIAAW; physical properties from PubChem (US National Library of Medicine). Values that have never been measured are shown as “not measured” rather than estimated.
Related Calculators
Frequently Asked Questions
What is the atomic mass of Niobium?
The standard atomic weight of Niobium is 92.906 u, as published by IUPAC's Commission on Isotopic Abundances and Atomic Weights.
How many protons, neutrons and electrons does Niobium have?
Niobium has 41 protons, because the atomic number is the proton count and that is what makes an atom Niobium at all. A neutral Niobium atom has the same number of electrons, 41. The neutron count varies by isotope; the most common one has about 52, since 93 − 41 = 52.
What is the electron configuration of Niobium?
The electron configuration of Niobium is [Kr] 5s¹ 4d⁴. Its electrons are arranged 2, 8, 18, 12, 1 across 5 shells.
Is Niobium a metal?
Yes. Niobium is classified as a transition metal, on the metallic side of the table.
What group and period is Niobium in?
Niobium is in group 5 (the vanadium group), period 5, in the d-block. The group is its column and the period is its row.
What is the charge of Niobium?
Niobium most commonly forms a 5+ ion. Like most transition metals it has several accessible oxidation states, so the charge depends on the compound. Across all its compounds it shows oxidation states of +3, +5.
What is the melting point of Niobium?
Niobium melts at 2,477 °C and boils at 4,744 °C. That puts it in the solids at everyday temperatures.
What is Niobium used for?
Superconducting magnets in MRI and the LHC, High-strength low-alloy steels, Jet-engine superalloys, Hypoallergenic jewellery. Niobium is a soft, ductile metal that becomes superconducting when cold, and it is the alloy of choice for MRI and particle-accelerator magnets.
Who discovered Niobium, and where does its name come from?
Niobium (Nb) was discovered by Charles Hatchett in 1801. The name comes from Niobe, daughter of Tantalus in Greek myth.