073Transition metal · Group 5 · Period 6
Tantalum
Tantalum (Ta) is element 73, a transition metal in the d-block — group 5, period 6. It is a solid at room temperature with 6 electron shells (2, 8, 18, 32, 11, 2) and an atomic mass of 180.947882 u.
- Atomic mass
- 180.9 u
- Phase · STP
- solid
- Melting
- 3290 K · 3017 °C
- Boiling
- 5731 K · 5458 °C
- Electronegativity
- 1.5
- Density
- 16.69 g/cm³
Photograph — Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/tantalum.php
Emission spectrum
The visible light Tantalum emits when energised — its unique spectral fingerprint.
Identity
- Atomic number
- 73
- Standard atomic weight
- 180.9 u
- Category
- Transition metal
- Group
- 5
- Period
- 6
- Block
- d-block
- Oxidation states
- +5
Physical properties
- Melting point
- 3290 K · 3017 °C
- Boiling point
- 5731 K · 5458 °C
- Density
- 16.69 g/cm³
- Molar heat capacity
- 25.36 J/(mol·K)
- Atomic radius
- 217 pm
- Electron affinity
- 31 kJ/mol
Atomic structure
73protons
108neutrons
73electrons
2valence e⁻
- Noble-gas notation
- [Xe] 4f14 5d3 6s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d3
- Electrons per shell
- 2, 8, 18, 32, 11, 2
Periodic trends
Where Tantalum ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
7611
1.5k2
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1802
- Discovered by
- Anders Gustaf Ekeberg
- Named by
- —
- Appearance
- gray blue