ElementsWhat is tantalum?
Tantalum is a hard, blue-grey metal that resists almost all acids.
What is tantalum used for?
Tiny capacitors in phones and computers, surgical implants, and equipment for the chemical industry.
Where the name comes from
From Tantalus of Greek myth.
Key facts
- Symbol
- Ta
- Atomic number
- 73
- Atomic mass
- 180.9479 u
- Family
- Transition metal
- Period
- 6
- Group
- 5
- Block
- d
- State at room temperature
- Solid
- Melting point
- 3,017 °C (3,290 K, 5,462 °F)
- Boiling point
- 5,458 °C (5,731 K, 9,856 °F)
- Density
- 16.4 g/cm³
- Electrons per shell
- 2, 8, 18, 32, 11, 2
- Electron configuration
- [Xe]6s2 4f14 5d3
- Common oxidation states
- +5
- Electronegativity (Pauling)
- 1.5
- First ionisation energy
- 7.89 eV
- Electron affinity
- 0.322 eV
- Atomic radius (van der Waals)
- 217 pm
- Discovered
- 1802
Place in the periodic table
Tantalum is element number 73. It sits in period 6 (row 6) of the periodic table, in group 5 (column 5), and belongs to the d-block. Just before it comes hafnium (72), and just after it comes tungsten (74). In the same column, niobium is above it and dubnium is below it. Elements in one column tend to behave alike.
Family: Transition metals.
Physical properties
At room temperature tantalum is a solid. It melts at 3,017 °C and boils at 5,458 °C, so it stays liquid over a range of 2,441 degrees. Its density is 16.4 grams per cubic centimetre, so a one-litre block would weigh about 16.4 kilograms. By density it ranks 10th among the 96 elements with a measured value. It has the 5th highest melting point of all elements.
Inside the atom
An atom of tantalum has 73 protons in its nucleus and, when neutral, 73 electrons around it. The electrons are arranged in 6 shells: 2, 8, 18, 32, 11, 2. The outermost shell holds 2 electrons. Written in full, the electron configuration is [Xe]6s2 4f14 5d3.
Its electronegativity on the Pauling scale is 1.5. This number shows how strongly an atom pulls shared electrons towards itself: fluorine, the strongest, is 3.98. Removing one electron from an atom takes 7.89 electronvolts (about 761 kilojoules per mole). One mole of tantalum weighs 180.9479 grams, so a single gram contains about 3.33 × 1021 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains tantalum with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.