41 Nb Niobium 92.906
Transition metal d-block Period 5 Group 5

Niobium

Nb · Element 41 · Transition metal

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A superconducting metal that carries the current in every MRI magnet on Earth.

State at 20°C Solid
Atomic mass 92.906 u
Electron configuration[Kr] 4d⁴ 5s¹
40Zr All 118 42Mo

Structure

The niobium atom

Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.

Orbital cloud

Measured values

Property sheet

Every bar shows where niobium sits among all 118 elements for that property.

Physical

Density 8.57 g/cm³ 53%
Melting point 2750 K 95%
Boiling point 5017 K 94%
Specific heat 0.265 J/g·K
Thermal conductivity 53.7 W/m·K 67%

Atomic

Atomic radius 146 pm 39%
Covalent radius 164 pm
Van der Waals radius 207 pm

Electronic

Electronegativity 1.6 49%
Ionisation energy 652.2 kJ/mol 44%
Electron affinity 85.9 kJ/mol 65%

Occurrence

Abundance in crust 20 mg/kg 73%

Identity

SymbolNb
Atomic number41
Atomic mass92.9064 u
CategoryTransition metal
Blockd
Crystal structurebody-centered cubic
Oxidation states-3, -1, 0, +1, +2, +3, +4, +5
Discovered1801
Discovered byCharles Hatchett

Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.

Same element, different neutrons

Isotopes of niobium

All niobium atoms have the same number of protons, 41, and differ only in their number of neutrons: those variants are its isotopes. The most common, Nb-93, has 52 neutrons and makes up 100% of natural niobium.

Isotopes of niobium found in nature, with their share of the natural element
ISOTOPE Neutrons Natural Abundance Half-life Decay Mode
Nb-93 most common 52 100% Stable —

Here the classroom shortcut, rounded atomic mass (92.906) minus atomic number, gives the same answer: 52.

Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.

Size, to scale

How big is a niobium atom?

Radius 146 pm — that is 0.146 nm, so about 3.42 million of them side by side would span a millimetre.

Thermal range

Solid, liquid, gas — and when

Niobium is liquid over a 2267 K window, from 2750 K to 5017 K.

Where it sits

Position in the table

Niobium sits in period 5, group 5. Everything in group 5 shares the same outer-electron count, which is why they behave so similarly.

Other transition metals

21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 39Y 40Zr 42Mo 43Tc 44Ru 45Rh
All transition metals

The story

What niobium is, and how we found it

Niobium (Nb) is element 41, a soft, gray, ductile transition metal in group 5, between vanadium and tantalum. It melts at 2,477 °C (2,750 K) and has a density of 8.57 g/cm³. Below 9.25 K it becomes a superconductor, at the highest temperature of any element at normal pressure, and its alloys niobium-titanium and niobium-tin are the basis of superconducting magnets.

Atomic structure and isotopes

Niobium has 41 electrons in five shells, arranged 2, 8, 18, 12, 1, with the configuration [Kr] 4d⁴ 5s¹. Its most common oxidation state is +5, as in niobium pentoxide.

Natural niobium is a single stable isotope, niobium-93.

The discovery of niobium

Columbium (1801)

In 1801 the English chemist Charles Hatchett analyzed a black mineral that had been sent to the British Museum from Connecticut and found a new element in it. He named it columbium, after Columbia, a poetic name for America.

Confusion with tantalum

In 1802 Anders Ekeberg found tantalum, and in 1809 William Hyde Wollaston concluded, wrongly, that columbium and tantalum were the same element.

Niobium (1844 to 1866)

In 1844 Heinrich Rose showed that tantalite ores contained a second element besides tantalum and named it niobium, after Niobe, the daughter of Tantalus in Greek myth. Christian Wilhelm Blomstrand first isolated the metal in 1864, and between 1864 and 1866 Jean Charles Galissard de Marignac proved that niobium and tantalum were distinct.

One element, two names

Columbium and niobium turned out to be the same element. IUPAC adopted the name niobium in 1949, although American metallurgists went on using columbium for decades.

Applications

What niobium is used for

Steel

About 90% of niobium is used as ferroniobium in steel. Adding a few hundredths of a percent produces high-strength low-alloy steels, which are stronger and tougher at lower weight, for oil and gas pipelines, car bodies, bridges and buildings.

Superconducting magnets and accelerators

  • MRI scanners: almost all MRI magnets are wound with niobium-titanium wire cooled by liquid helium.
  • Particle physics and fusion: niobium-titanium magnets steer the beams of the Large Hadron Collider, and niobium-tin magnets are used in the ITER fusion reactor and the LHC upgrade.
  • Accelerator cavities: cavities of pure niobium accelerate particles in machines such as the European XFEL.

Jet engines and other uses

  • Superalloys: nickel alloys containing niobium, such as Inconel 718, are used in jet engines and gas turbines.
  • Rockets: the niobium alloy C-103 is used for rocket nozzles, for example on the Apollo service module engine.
  • Electronics and optics: niobium capacitors, and lithium niobate crystals in optical modulators and phone filters.

In everyday life

  • Cars and pipelines: modern car bodies and gas pipelines use niobium microalloyed steel.
  • Hospitals: MRI scanners rely on niobium-titanium superconducting wire.
  • Jewelry: niobium is used for body piercings and earrings because it rarely causes allergies, and anodizing gives it bright colors without dyes.
  • Coins: Austria and other countries have issued bimetallic coins with colored niobium centers.

Where it comes from

Natural occurrence

20 mg/kg of Earth's crust · more abundant than 73% of elements

Abundance

Niobium makes up about 20 parts per million of Earth's crust. It always occurs together with tantalum, which is chemically almost identical.

Minerals

  • Pyrochlore, a complex niobium oxide found in carbonatite rocks, the main commercial source.
  • Columbite, an iron and manganese niobate that grades into tantalite; the two together are known as coltan.

Production

Brazil produces more than 90% of the world's niobium and Canada most of the rest (USGS). Most Brazilian niobium comes from the carbonatite deposit at Araxá.

Handling

Safety

Health hazards

Niobium metal is of low toxicity and is used in implants and jewelry because the body tolerates it well. Some niobium compounds, such as niobium pentachloride, are corrosive and react with moisture to release hydrogen chloride. Dust may irritate the eyes and lungs.

Fire

Niobium powder can ignite in air, and fine dust can form explosive mixtures. Store powders dry and away from ignition sources, and fight metal fires with a Class D extinguisher or dry sand.

Superconducting systems

The main hazards of niobium magnets come from their surroundings: the strong magnetic fields of MRI and research magnets pull iron objects toward them, and the liquid helium that cools them can cause cold burns and suffocation if it escapes.

Keep exploring

Use niobium in the tools

Quick answers

Niobium: common questions

What is niobium?

Niobium (symbol Nb) is element 41 on the periodic table, a transition metal in period 5, group 5. A superconducting metal that carries the current in every MRI magnet on Earth. At room temperature it is a solid.

What is the electron configuration of niobium?

Niobium's ground-state electron configuration is [Kr] 4d⁴ 5s¹, giving 5 occupied shells with the distribution 2, 8, 18, 12, 1.

What are the melting and boiling points of niobium?

Niobium melts at 2750 K (2476.9 °C) and boils at 5017 K (4743.9 °C). That puts it among the most refractory elements — it stays solid at temperatures that vaporise most metals.

What is the atomic mass of niobium?

The standard atomic weight of niobium is 92.906 u. That is a weighted average across its naturally occurring isotopes, which is why it is rarely a whole number.

How many neutrons does niobium have?

The most common niobium atom, Nb-93, has 52 neutrons: its mass number, 93, minus its atomic number, 41. It makes up 100% of natural niobium. The classroom shortcut, rounded atomic mass (92.906) minus atomic number, gives the same 52.

How dense is niobium?

Niobium has a density of 8.57 g/cm³. Water is 1.0 g/cm³, so a block of niobium is about 8.6× heavier.

What is the electronegativity of niobium?

Niobium has a Pauling electronegativity of 1.6. The scale runs from 0.70 (francium, the least greedy for electrons) to 3.98 (fluorine, the most). Values in this middle band tend to form covalent rather than strongly ionic bonds.

Who discovered niobium, and when?

Niobium was discovered in 1801 by Charles Hatchett. Origin of the name: Niobe, daughter of Tantalus.

How common is niobium on Earth?

Niobium makes up about 20 mg/kg of the Earth's crust — uncommon, but not rare.

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