Tantalum (Ta)
Element 73 · Transition metal · atomic mass 180.95 u · group 5, period 6
Electron shells: 2, 8, 18, 32, 11, 2
Tantalum forms an extremely thin, stable oxide layer, which makes exceptionally compact capacitors. It is also inert enough for surgical implants.
Tantalum capacitors are why phones shrank — nothing else packs that much capacitance into that space.
- Atomic number
- 73
- Atomic mass
- 180.95 u
- Electron configuration
- [Xe] 6s² 4f¹⁴ 5d³
- Group · period · block
- 5 · 6 · d
- Oxidation states
- +5
- Electronegativity
- 1.5 (Pauling)
- Melting point
- 3,017 °C
- Boiling point
- 5,458 °C
- Density
- 16.4 g/cm³
- State at 20 °C
- Solid
- Appearance
- Grey-blue, hard metal
- Discovered
- Anders Gustaf Ekeberg, 1802
73 protons, and 73 electrons when neutral
IUPAC standard atomic weight
Vanadium group
What Tantalum is used for
- Capacitors in phones and electronics
- Surgical implants and bone repair
- Chemical plant linings
- Superalloys and carbide tools
Atomic structure of Tantalum
A neutral tantalum atom has 73 protons and 73 electrons. Its most common isotope carries about 108 neutrons, which is where the mass number 181 comes from. Change the neutron count and you have a different isotope of tantalum; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 18, 32, 11, 2. In orbital notation that is [Xe] 6s² 4f¹⁴ 5d³. 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 Tantalum's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Tantalum 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.
Discovery and naming
Tantalum was discovered by Anders Gustaf Ekeberg in 1802. Its name comes from Tantalus of Greek myth.
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 Tantalum?
The standard atomic weight of Tantalum is 180.95 u, as published by IUPAC's Commission on Isotopic Abundances and Atomic Weights.
How many protons, neutrons and electrons does Tantalum have?
Tantalum has 73 protons, because the atomic number is the proton count and that is what makes an atom Tantalum at all. A neutral Tantalum atom has the same number of electrons, 73. The neutron count varies by isotope; the most common one has about 108, since 181 − 73 = 108.
What is the electron configuration of Tantalum?
The electron configuration of Tantalum is [Xe] 6s² 4f¹⁴ 5d³. Its electrons are arranged 2, 8, 18, 32, 11, 2 across 6 shells.
Is Tantalum a metal?
Yes. Tantalum is classified as a transition metal, on the metallic side of the table.
What group and period is Tantalum in?
Tantalum is in group 5 (the vanadium group), period 6, in the d-block. The group is its column and the period is its row.
What is the charge of Tantalum?
Tantalum most commonly forms a 5+ ion. Like most transition metals it has several accessible oxidation states, so the charge depends on the compound.
What is the melting point of Tantalum?
Tantalum melts at 3,017 °C and boils at 5,458 °C. That puts it in the solids at everyday temperatures.
What is Tantalum used for?
Capacitors in phones and electronics, Surgical implants and bone repair, Chemical plant linings, Superalloys and carbide tools. Tantalum forms an extremely thin, stable oxide layer, which makes exceptionally compact capacitors.
Who discovered Tantalum, and where does its name come from?
Tantalum (Ta) was discovered by Anders Gustaf Ekeberg in 1802. The name comes from Tantalus of Greek myth.