Tantalum: the essentials
Tantalum is a greyish silver, heavy, and very hard metal. When pure, it is ductile and can be drawn into fine wire, which can be used as a filament for evaporating metals such as aluminium. Tantalum is almost completely immune to chemical attack at temperatures below 150°C, and is attacked only by hydrofluoric acid, acidic solutions containing the fluoride ion, and free sulphur trioxide. The element has a melting point exceeded only by tungsten and rhenium.
Small and large samples of tantalum wire like this, as well as foil, sheet, insulated wire, mesh and rod, can be purchased via their web catalogue from Advent Research Materials via their web catalogue.
Tantalum: historical information
Niobium was discovered in 1802 by Anders Gustaf Ekeberg, but many chemists thought niobium and tantalum were one and the same. Some felt that perhaps tantalum was an allotrope of niobium. Later, Rose, in 1844, and Marignac, in 1866, showed that niobic and tantalic acids were two different acids.
The first relatively pure tantalum was produced by von Bolton in 1907.
Tantalum around us Read more »
Tantalum has no biological role. Possibly some tantalum compounds cause tumours.
Tantalum is found mainly in the minerals tantalite [(Fe,Mn)Ta2O6] (easily confused with columbite, the niobium analogue of tantalite) and euxenite. Ores are found in Australia, Brazil, Mozambique, Thailand, Portugal, Nigeria, Zaire and Canada. It is also a byproduct from the extraction of tin.
|Location||ppb by weight||ppb by atoms||Links|
|Human||(no data) ppb by weight||(no data) atoms relative to C = 1000000|
Physical properties Read more »
Heat properties Read more »
- Melting point: 3290 [3017 °C (5463 °F)] K
- Boiling point: 5731 [5458 °C (9856 °F)] K
- Enthalpy of fusion: |203| kJ mol-1
Crystal structure Read more »
The solid state structure of tantalum is: bcc (body-centred cubic).
Tantalum: orbital properties Read more »
Tantalum atoms have 73 electrons and the shell structure is 188.8.131.52.11.2. The ground state electronic configuration of neutral Tantalum is [Xe].4f14.5d3.6s2 and the term symbol of Tantalum is 4F3/2.
- Pauling electronegativity: 1.5 (Pauling units)
- First ionisation energy: 761 kJ mol‑1
- Second ionisation energy: 1500 kJ mol‑1
Isolation: isolation of tantalum appears to be complicated. Tantalum minerals usually contain both niobium and tantalum. Since they are so similar chemically, it is difficult to separate them. Tantalum can be extracted from the ores by first fusing the ore with alkali, and then extracting the resultant mixture into hydrofluoric acid, HF. Current methodology involves the separation of tantalum from these acid solutions using a liquid-liquid extraction technique. In this process tantalum salts are extracted into the ketone MIBK (methyl isobutyl ketone, 4-methyl pentan-2-one). The niobium remains in the HF solution.
After conversion to the oxide, metallic tantalum can be made by reduction with sodium or carbon. Electrolysis of molten fluorides is also used.
Tantalum isotopes Read more »
Tantalum has only two isotopes and one of them, Ta-180, has one of the lowest natural abundances of all naturally occurring isotopes (0.012%). Ta-180 has only been produced in minute quantities and is very expensive. Ta-181 can be used for the production of W-178 which decays to Ta-178. Ta-178 emits low energy gamma rays which can be used for imaging purposes.
|180Ta||179.947462 (4)||0.012 (2)||8|
|181Ta||180.947992 (3)||99.988 (2)||7/2||2.371|