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73Ta180.95

Tantalum (Ta)

Transition metal

Tantalum is the reason smartphones are small: its oxide layer stores charge so efficiently that tantalum capacitors pack maximum capacitance into minimum space. It is also completely body-inert, ideal for implants.

Group: 5Period: 6Block: dState at 25 °C: Solid

Position on the periodic table

Fun fact: Tantalum capacitors sit inside virtually every smartphone — a key reason “coltan” mining became geopolitically important.

Atomic properties

Atomic number73
Atomic mass180.948 amu
Electron configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d3
Noble gas shorthand[Xe] 4f14 5d3 6s2
Electrons per shell2, 8, 18, 32, 11, 2
Valence electrons (outer shell)2
Common oxidation states+5
Electronegativity (Pauling)1.5
Covalent radius (approx.)170 pm
First ionization energy761 kJ/mol
Electron affinity31 kJ/mol

Physical properties

State at 25 °CSolid
Density16.69 g/cm³
Melting point3016.8 °C (3290 K)
Boiling point5457.9 °C (5731 K)
Appearancegray blue
RadioactiveNo
OriginOccurs naturally

Electron configuration of tantalum

Tantalum's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d3, usually shortened to [Xe] 4f14 5d3 6s2. Its electrons occupy 6 shells (2, 8, 18, 32, 11, 2), placing it in period 6 of the d-block. Explore it interactively in the electron configuration calculator.

Uses of tantalum

  • Miniature capacitors for phones and laptops
  • Surgical implants and bone plates
  • Chemical plant linings
  • Superalloy additions

Biological role: None — but exceptionally biocompatible.

Occurrence: Mined as tantalite/coltan, mainly in Africa, Brazil and Australia.

Common compounds of tantalum

Ta2O5

Tantalum pentoxide

Molar mass →

History and discovery

Discovered: 1802 — Anders Gustaf Ekeberg. Name origin: From Tantalus of Greek myth, condemned to stand in water he could never drink — the metal 'cannot absorb' acid.

Anders Gustaf Ekeberg discovered tantalum in 1802; confusion with niobium took decades to resolve.

Safety notes

Inert and safe in bulk; conflict-mineral sourcing is the main ethical concern.

Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.

Practice questions

Quick practice: Tantalum

1. What is the chemical symbol of Tantalum?

2. What is the atomic number of Tantalum?

3. Which category does Tantalum belong to?

4. What is the state of Tantalum at room temperature?

5. Which period of the periodic table is Tantalum in?

Want more? Try the full quizzes →

Tantalum FAQs

What is the atomic number of tantalum?

Tantalum's atomic number is 73 — every tantalum atom has 73 protons in its nucleus.

What is the symbol for tantalum?

Ta. From Tantalus of Greek myth, condemned to stand in water he could never drink — the metal 'cannot absorb' acid.

Is tantalum a metal, nonmetal, or metalloid?

Tantalum is classified as a transition metal.

What state is tantalum at room temperature?

At about 25 °C, tantalum is a solid. It melts at 3016.8 °C.

What is tantalum used for?

Key uses include: miniature capacitors for phones and laptops; surgical implants and bone plates; chemical plant linings.

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