73
Ta
Tantalum
181
Tantalum (Ta)
Transition MetalGroup 5Period 6d-block-block
Tantalum is a chemical element with symbol Ta and atomic number 73. Previously known as tantalium, its name comes from Tantalus, an antihero from Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant.
Latin name: Tantalum
Atomic Number
73
Atomic Mass
181 g/mol
Phase (STP)
Solid
Electron Config.
[Xe] 4f¹⁴ 5d³ 6s²
General
SymbolTa
Atomic Number73
Atomic Mass181 g/mol
CategoryTransition Metal
Group5
Period6
Blockd-block
Electron Configuration[Xe] 4f¹⁴ 5d³ 6s²
Valence Electrons5
Colourgray blue metallic
Appearancegray blue
CAS NumberCAS7440-25-7
Physical Properties
Phase (STP)Solid
Density16.69 g/cm³
Melting Point3016.85°C · 5462.33°F · 3290.00 K
Boiling Point5457.85°C · 9856.13°F · 5731.00 K
Atomic Properties
Atomic Radius217 pm
Electronegativity1.5 Pauling
Ionization Energy761 kJ/mol
Oxidation States+5, +4, +3, +2
Ion ChargeTa2+/Ta3+/Ta4+/Ta5+
Thermodynamic
Molar Heat25.36 J/(mol·K)
Crystal Structure
Crystal Structurebody-centered cubic
Mechanical Properties
Mohs Hardness6
Nuclear & Hazards
Half-lifestable
Abundance
In Universe0.000003%
In Sun0.000002%
In Earth's Crust0.00005999999999999999%
Discovery & History
Discovery Year1802
Discovered ByAnders Gustaf Ekeberg
Country of DiscoverySweden
Isotopes of Tantalum
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Ta-180m | 0.01201% | Stable | — |
| Ta-181 | 99.98799% | Stable | — |