Atomic number 73 · Transition metal
Tantalum Ta
Tantalum (Ta), element 73, is a heavy, hard, blue-grey transition metal. It melts at a very high temperature and shrugs off almost every acid, and it is the key material in the tiny, high-capacity capacitors inside phones and computers.
Key properties
| Atomic number | 73 |
|---|---|
| Atomic weight | 180.95 (CIAAW 2024 abridged standard atomic weight) |
| Category | Transition metal |
| Group | 5 |
| Period | 6 |
| Block | d |
| State (25 °C, 1 atm) | Solid |
| Melting point | 3290 K (3016.8 °C) |
| Boiling point | 5731 K (5457.9 °C) |
| Density | 16.4 g/cm³ |
| Electronegativity (Pauling) | 1.5 |
| Atomic radius (van der Waals) | 217 pm |
| First ionization energy | 7.89 eV |
| Electron affinity | 0.322 eV |
| Oxidation states | +5 |
| Discovered | 1802 |
Electron configuration
- Condensed
- [Xe]6s2 4f14 5d3
- Full
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2
- Electrons per shell
- 2 · 8 · 18 · 32 · 11 · 2
Orbital diagram
Position in the table
Discovery
In 1802 Anders Gustaf Ekeberg at Uppsala found the oxide of a new element in minerals from Finland and Sweden. Only a year earlier, in 1801, Charles Hatchett in England had announced "columbium" from a similar mineral, and in 1809 William Hyde Wollaston concluded that the two were the same element.
The confusion lasted decades. In 1844 Heinrich Rose in Germany showed that tantalum ores contained a second element, which he called niobium, and in 1866 Jean Charles Galissard de Marignac clearly separated the two. Ductile, pure tantalum was first produced in 1903 by Werner von Bolton, and it briefly served as a light-bulb filament before tungsten took over.
Origin of the name
The name comes from Tantalus, the figure of Greek myth condemned to stand in water he could never drink. Ekeberg thought of him because tantalum oxide sits in acid without absorbing it. Tantalum's chemical twin niobium is named after Niobe, Tantalus's daughter.
Main uses
- Electrolytic capacitors: an extremely thin oxide film grown on tantalum powder stores a lot of charge in a small volume, so tantalum capacitors are used in phones, laptops, automotive electronics and medical devices. This is one of the largest uses of the metal.
- Medical implants: tantalum is highly biocompatible and bonds well with bone, so it is used in joint implants, skull plates and surgical clips.
- Chemical equipment: its resistance to nearly all acids makes it ideal for linings and heat exchangers.
- Alloys and tools: it strengthens superalloys for jet engines, and tantalum carbide is used in cutting tools.
Isotopes
Almost all natural tantalum (about 99.99%) is stable tantalum-181. The tiny remainder is tantalum-180m, an excited nuclear isomer that has never been observed to decay, making it one of the rarest primordial nuclides. Artificial tantalum-182, with a half-life of about 114 days, is used as a gamma source.
In everyday life
Many of the small yellow or black rectangular parts on a phone's circuit board are tantalum capacitors. Coltan, a major tantalum ore, has financed armed groups in eastern Democratic Republic of the Congo, so it is regulated as a conflict mineral and electronics makers run supply-chain tracing programmes. Tantalum metal is very inert in the body and has very low toxicity.
Good to know
- Tantalum and niobium are named after a father and daughter from Greek mythology.
- Tantalum-180m is a naturally occurring nuclear isomer whose decay has never been observed.
- Tantalum melts above 3,000 °C, among the highest melting points of all metals.
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.