Niobium
Definition and meaning of Niobium in chemistry.
![Niobium element card: symbol Nb, atomic number 41, atomic mass 92.906, electron configuration [Kr] 4d⁴ 5s¹, oxidation states +5, Transition metal, group 5, period 5, solid at room temperature.](/assets/images/terms/niobium-chemical-element.webp)
Niobium is a light gray, crystalline, and ductile transition metal. It has the chemical symbol Nb and an atomic number of 41. It shares very similar physical and chemical properties with the heavier element tantalum.
In more detail
Niobium sits in group 5 and period 5 of the periodic table. It is a refractory metal, meaning it is highly resistant to heat and wear. Manufacturers highly value its remarkable ability to enhance the strength of metal alloys.
An alloy is a solid mixture of two or more metallic elements. Niobium becomes a superconductor when cooled to extremely low cryogenic temperatures. A superconductor is a material that conducts electricity with zero resistance.
Scientists frequently mix it with titanium to build powerful superconducting magnets. At high temperatures, niobium reacts readily with nonmetals like carbon and oxygen. However, it quickly forms an extremely stable oxide layer at room temperature.
This passive layer protects the metal from corrosion by most aggressive acids. In nature, niobium is closely linked with tantalum in geological deposits. These two elements are notoriously challenging for chemists to separate from each other.
This difficulty arises because they have almost identical atomic sizes. Niobium can display oxidation states ranging from -1 to +5. The +5 state is the most common and chemically stable form. This state creates compounds like niobium pentoxide, which helps manufacture optical glasses.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Nb |
| Atomic number | 41 |
| Atomic mass | 92.906 u |
| Category | Transition-Metal |
| Melting point | 2477 °C |
| Year discovered | 1801 |
Engineers frequently alloy niobium with steel in very small, carefully measured quantities. This creates a high-strength, low-alloy structural steel that is incredibly tough. Manufacturers use this advanced steel extensively to build modern automobile bodies. Construction crews also rely on it for massive bridges and high-pressure gas pipelines. The added niobium ensures these large structures remain strong without adding excessive weight.
Frequently asked questions
Why was niobium formerly called columbium?
Its discoverer originally named it columbium after the mineral columbite. However, the international chemistry community officially adopted the name niobium in 1949.
Do jewelry makers use niobium?
Yes, niobium is hypoallergenic and very safe for sensitive skin. Jewelers can anodize it to display vibrant colors without using any artificial dyes.
Related terms
Sources & references
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