CAS Number7440-34-8
PubChem CIDna
Atomic Radius-
Atomic Volume22,54
Atomic Weight[227]
Boiling Point3 198
Bulk Modulus
Crystal StructureFace Centered Cubic
Covalent Radius215
Electrical Resistivity
Electron Configuration[Rn] 6d1 7s2
Electrons per shell2, 8, 18, 32, 18, 9, 2
Heat of Fusion14
Heat of Vaporization400
Ionization Potential5,17
Magnetic Ordering
Magnetic Susceptibility
Mass Number89
Melting Point1 050
Atomic Number227
Oxidation States3
Poisson Ratio
Shear Modulus
Specific Heat Capacity0,12
Thermal Conductivity0,12
Van der Waals radius
Young's Modulus
Abundance in Earth's crustna
Abundance in Universena
Ac Aktinis 89 (227) 3 7 f 89 1050.0 3200.0 [Rn] 6d1 7s2 2 8 18 32 18 9 2 10.1 N/A Silver Cubic: Face centered 1.1 {"1":"499","2":"1170"} 499 3 1.88 22.5 0.12 12.0 1 21.7865 y 31.4311y BetaDecay Solid, Actinide, Radioactive, Natural ak-TIN-i-em Heavy, silvery-white, very radioactive metal It has no significant commercial applications. Extremely rare, found in all uranium ores. Usually obtained by treating radium with neutrons in a reactor. 0BlpjWBYW0k Actinium
Tantalum was discovered in Sweden in 1802 by Anders Ekeberg in the minerals tantalite from Finland and yttrotantalite from Sweden.

Unfortunately, William Hyde Wollaston claimed Ekeberg's new element was actually niobium, which had also been discovered in 1802.

In 1846, German chemist Heinrich Rose finally proved beyond doubt that tantalum and niobium were different elements. Named after Tantalos, a Greek mythological character, father of Niobe 89 1899 Andre Debierne France From the Greek word "aktinos" meaning "ray"

Isotopes of Tantalum

Standard Atomic Weight


Stable Isotopes

Unstable Isotopes

206Ac 207Ac 208Ac 209Ac 210Ac 211Ac 212Ac 213Ac 214Ac 215Ac 216Ac 217Ac 218Ac 219Ac 220Ac 221Ac 222Ac 223Ac 224Ac 225Ac 226Ac 227Ac 228Ac 229Ac 230Ac 231Ac 232Ac 233Ac 234Ac 235Ac 236Ac

Tantalum is considered to be non-toxic
Tantalum occurs principally in the mineral columbite-tantalite
Tantalum is used in the electronics industry for capacitors and high power resistors.

The high melting point and oxidation resistance lead to the use of the metal in the production of vacuum furnace parts.

Tantalum oxide is used to make special glass with high index of refraction for camera lenses.