Tantalum

Tantalum, ₇₃Ta
Tantalum
Pronunciation	/ˈtæntələm/ (TAN-təl-əm)
Appearance	gray blue
Standard atomic weight Ar°(Ta)
	180.94788±0.00002; 180.95±0.01 (abridged);
Tantalum in the periodic table
	hafnium ← tantalum → tungsten
Atomic number (Z)	73
Group	group 5
Period	period 6
Block	d-block
Electron configuration	[Xe] 4f14 5d3 6s2
Electrons per shell	2, 8, 18, 32, 11, 2
Physical properties
Phase at STP	solid
Melting point	3290 K (3017 °C, 5463 °F)
Boiling point	5731 K (5458 °C, 9856 °F)
Density (at 20° C)	16.678 g/cm3
when liquid (at m.p.)	15 g/cm3
Heat of fusion	36.57 kJ/mol
Heat of vaporization	753 kJ/mol
Molar heat capacity	25.36 J/(mol·K)
Atomic properties
Oxidation states	common: +5; −3, −1, 0, +1, +2, +3, +4
Electronegativity	Pauling scale: 1.5
Ionization energies	1st: 761 kJ/mol ; 2nd: 1500 kJ/mol ; ;
Atomic radius	empirical: 146 pm
Covalent radius	170±8 pm
	Spectral lines of tantalum
Other properties
Natural occurrence	primordial
Crystal structure	body-centered cubic (bcc) (cI2)
Lattice constant	a = 330.29 pm (at 20 °C)
Thermal expansion	6.3 µm/(m⋅K) (at 25 °C)
Thermal conductivity	57.5 W/(m⋅K)
Electrical resistivity	131 nΩ⋅m (at 20 °C)
Magnetic ordering	paramagnetic
Molar magnetic susceptibility	+154.0×10−6 cm3/mol (293 K)
Young's modulus	186 GPa
Shear modulus	69 GPa
Bulk modulus	200 GPa
Speed of sound thin rod	3400 m/s (at 20 °C)
Poisson ratio	0.34
Mohs hardness	6.5
Vickers hardness	870–1200 MPa
Brinell hardness	440–3430 MPa
CAS Number	7440-25-7
History
Naming	after Tantalus, Greek mythological figure
Discovery	Anders Gustaf Ekeberg (1802)
Recognized as a distinct element by	Heinrich Rose (1844)
Isotopes of tantalum v; e;
β−	180W
	Category: Tantalum; view; talk; edit; \| references

Tantalum is a chemical element; it has symbol Ta and atomic number 73. It is named after Tantalus, a figure in Greek mythology.^[11] Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as components of strong high-melting-point alloys. It is a group 5 element, along with vanadium and niobium, and it always occurs in geologic sources together with the chemically similar niobium, mainly in the mineral groups tantalite, columbite, and coltan.

The chemical inertness and very high melting point of tantalum make it valuable for laboratory and industrial equipment such as reaction vessels and vacuum furnaces. It is used in tantalum capacitors for electronic equipment such as computers. It is being investigated for use as a material for high-quality superconducting resonators in quantum processors.

^ "Standard Atomic Weights: Tantalum". CIAAW. 2005.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
^ ^a ^b ^c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
^ Ta(–3) occurs in Ta(CO)_₅³⁻; see John E. Ellis (2003). "Metal Carbonyl Anions: from [Fe(CO)₄]₂⁻ to [Hf(CO)₆]₂⁻ and Beyond†". Organometallics. 22 (17): 3322–3338. doi:10.1021/om030105l.
^ ^a ^b ^c ^d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.
^ Ta(0) is known in Ta(CNDipp)₆; see Khetpakorn Chakarawet; Zachary W. Davis-Gilbert; Stephanie R. Harstad; Victor G. Young Jr.; Jeffrey R. Long; John E. Ellis (2017). "Ta(CNDipp)6: An Isocyanide Analogue of Hexacarbonyltantalum(0)". Angewandte Chemie International Edition. 56 (35): 10577–10581. doi:10.1002/anie.201706323. PMID 28697283. Additionally, Ta(0) has also been previously reported in Ta(bipy)₃, but this has been proven to contain Ta(V).
^ Ta(I) has been observed in CpTa(CO)₄; see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (2008). Lehrbuch der Anorganischen Chemie (in German) (102 ed.). Walter de Gruyter. p. 1554. ISBN 9783110206845.
^ Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
^ Euripides, Orestes

[CIAAW-1] "Standard Atomic Weights: Tantalum". CIAAW. 2005.

[CIAAW2021-2] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.

[Arblaster_2018-3] Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.

[4] Ta(–3) occurs in Ta(CO)_₅³⁻; see John E. Ellis (2003). "Metal Carbonyl Anions: from [Fe(CO)₄]₂⁻ to [Hf(CO)₆]₂⁻ and Beyond†". Organometallics. 22 (17): 3322–3338. doi:10.1021/om030105l.

[GE28-5] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.

[6] Ta(0) is known in Ta(CNDipp)₆; see Khetpakorn Chakarawet; Zachary W. Davis-Gilbert; Stephanie R. Harstad; Victor G. Young Jr.; Jeffrey R. Long; John E. Ellis (2017). "Ta(CNDipp)6: An Isocyanide Analogue of Hexacarbonyltantalum(0)". Angewandte Chemie International Edition. 56 (35): 10577–10581. doi:10.1002/anie.201706323. PMID 28697283. Additionally, Ta(0) has also been previously reported in Ta(bipy)₃, but this has been proven to contain Ta(V).

[7] Ta(I) has been observed in CpTa(CO)₄; see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (2008). Lehrbuch der Anorganischen Chemie (in German) (102 ed.). Walter de Gruyter. p. 1554. ISBN 9783110206845.

[magnet-8] Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[9] Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.

[NUBASE2020-10] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[11] Euripides, Orestes

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