Tantalum (Ta)

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Tantalum 73Ta180.948

Discovered in 1802 by A.G. Ekeberg at Uppsala, Sweden.

[Greek, Tantalos, father of Niobe of Greek mythology]

French: tantale
German: tantal
Italian: tantalio
Spanish: tántalo

Description: Tantalum is a shiny, silvery metal which is soft when pure. It is very resistant to corrosion due to an oxide film on its surface, but is is attacked by HF and molten alkalis. Tantalum is used in electronics, cutting tools, chemical plants and surgery.



Tantalum single crystal properties

State: Single crystal
Crystal structure: bcc
Production method: Floating zone
Standard size: diameter 6-12mm
thickness 1-2mm
Orientation: (100), (110) and (111)
Orientation accuracy: <2°, <1°, <0.4° or <0.1°
Polishing: as cut, one or two sides polished
Roughness of surface: <0.03µm
Purity: 99.99%
Typical analysis (ppm): C 3
H < 1
O 9
N < 5
Cu 1.60
Fe 1.80
Ni < 1
Pb 0.30
Si 0.30

Ga, Hf and Ta are below the detection limit

Materials properties

Density: 16.6 g/cm3
Melting point: 2995.85 °C / 3269 °K
Boiling point: 5424.85±100 °C / 5698±100 °K
Molar volume: 10.87 cm3
Thermal conductivity: 57.5 [300 K] Wm-1K-1
Coefficient of linear thermal expansion: 6.6 x 10-6 K-1
Electrical resistivity: 12.45x 10-8 [298 K] Wm
Mass magnetic susceptibility: +1.07 x 10-8(s) kg-1m3
Young's modulus: 185.7 GPa
Rigidity modulus: 69.2 GPa
Bulk modulus: 196.3 GPa
Poisson's ratio: 0.342
Radii: Ta5+ 64; Ta4+ 68; Ta3+ 72; atomic 143; covalent 13
Electronegativity: 1.5 (Pauling); 1.33 (Allred); 4.11 eV (absolute)
Effective nuclear charge: 3.30 (Slater); 9.53 (Clementi); 13.78 (Froese-Fischer)
Number of Isotopes (incl. nuclear isomers): 28
Issotope mass range: 159 -> 186
Crystal structure, (cell dimentions / pm), space group bcc
X-ray diffraction: mass absorption coefficients: CuKα 166 (µ/r) / cm2g-1
MoKα 95.4 (µ/r) / cm2g-1
Neutron scattering length: 0.691 b/10-12 cm
Thermal neutron capture cross-section: 20.6 sa / barns


Biological data

Biological role: none
Toxic intake: moderately poisonous by ingestion
Lethal intake: LD50 (chloride, oral, rat)= 1900 mg kg-1
Hazards: There are no cases of industrial poisoning caused by tantalum or its compounds. However, it is an experimental tumorigen.
Level in humans  
Blood: n.a., but low
Bone: c. 0.03 p.p.m.
Liver: n.a.
Muscle: n.a., but low
Daily dietary intake: 0.001 mg
Total mass of element in average [70 kg] person: c. 0.2 mg


Geological data

MineralFormulaDensityHardnessCrystal apperance
Columbite (Fe, Mn)(Ta, Nb)2O6 a group of Ferrotanta FeTa2O6
7.95 6 - 6.5 orth., bla Manganotan (Fe, Mn)(Ta, Nb)2O6
6.76 6 - 6.5 orth., bla Microlite (Na, Ca)2Ta2O6(O, OH, F)
6.42 5 - 5.5 cub., vitr Samarskite (Y, Ce, U, Fe)3(Nb, Ta, Ti)5O16
5.69 5 - 6 orth., vit Chief ore: columbite, samarskite


Chief ore: columbite, samarskite
World production: 840 tonnes/year
Main mining areas: Australia, Zaire, Brazil, Russia, Norway, Canada, Madagascar; mostly obtained as a by-product of tin extraction.
Reserves: n.a.
Specimen: available as foil, powder, rod or wire. Safe.


Sun: n.a. (relative to H = 1 x 1012)
Earth's crust: 2 p.p.m.
Residence time:  
Oxidation state: V

Source: Emsley, J. (1998) The Elements (3rd Edition)

Overview of elements with access to our shop

1 18
2 13 14 15 16 17
Li Be B C
Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se
Rb Sr Y Zr Nb Mo
Ru Rh Pd Ag Cd In Sn Sb Te I
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi
Ce Pr Nd
Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

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