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Element: Tantalum

General data

Element nameTantalum
Chemical symbolTa
Atomic number Z73
Year discovered1802
Standard state (25°C)Solid
CategoryTransition metal
Blockd
Atomic mass180.95
CPK color#4DA6FF

Physical properties

Melting point3290 K (3017 °C)
Boiling point5731 K (5458 °C)
Density16.4 g/cm³

Energy properties

First ionization energy7.89 eV
Electron affinity0.322 eV

Atomic structure

Protons73 (Atomic number)
Neutrons (Ta-181, most abundant isotope)108
Electrons73
Electron configuration[Xe] 6s² 4f¹⁴ 5d³
Oxidation states+5
Electronegativity (Pauling)1.5
Atomic radius (van der Waals)217 pm

Ionization energies - NIST ASD (73 states)

StateChargeIoniz. energy (eV)Type
Ta I0+7.549571 ± 0.000025measured
Ta II1+16.2 ± 0.5semi-empirical
Ta III2+23.1 ± 1.6calculated
Ta IV3+35 ± 1.7calculated
Ta V4+48.272 ± 0.025semi-empirical
Ta VI5+94.01 ± 0.05semi-empirical
Ta VII6+119 ± 6calculated
Ta VIII7+139 ± 7calculated
Ta IX8+159 ± 8calculated
Ta X9+180 ± 9calculated
Ta XI10+213 ± 11calculated
Ta XII11+235 ± 12calculated
Ta XIII12+262 ± 14calculated
Ta XIV13+304 ± 15calculated
Ta XV14+338 ± 17calculated
Ta XVI15+363 ± 19calculated
Ta XVII16+396 ± 20calculated
Ta XVIII17+439 ± 22calculated
Ta XIX18+482 ± 24calculated
Ta XX19+530 ± 30calculated
Ta XXI20+570 ± 30calculated
Ta XXII21+610 ± 30calculated
Ta XXIII22+660 ± 30calculated
Ta XXIV23+700 ± 30calculated
Ta XXV24+750 ± 40calculated
Ta XXVI25+790 ± 40calculated
Ta XXVII26+832 ± 10calculated
Ta XXVIII27+1064 ± 4calculated
Ta XXIX28+1110 ± 4calculated
Ta XXX29+1160 ± 4calculated
Ta XXXI30+1211 ± 4calculated
Ta XXXII31+1262 ± 4calculated
Ta XXXIII32+1313 ± 4calculated
Ta XXXIV33+1382 ± 5calculated
Ta XXXV34+1434 ± 5calculated
Ta XXXVI35+1490 ± 5calculated
Ta XXXVII36+1542 ± 5calculated
Ta XXXVIII37+1748 ± 4calculated
Ta XXXIX38+1799 ± 4calculated
Ta XL39+1857 ± 4calculated
Ta XLI40+1910 ± 4calculated
Ta XLII41+2053 ± 4calculated
Ta XLIII42+2113 ± 4calculated
Ta XLIV43+2254 ± 4calculated
Ta XLV44+2314.7 ± 1.9semi-empirical
Ta XLVI45+3898.7 ± 2.5measured
Ta XLVII46+4014 ± 4calculated
Ta XLVIII47+4143 ± 4calculated
Ta XLIX48+4278 ± 4calculated
Ta L49+4410 ± 4calculated
Ta LI50+4537 ± 4calculated
Ta LII51+4745 ± 4calculated
Ta LIII52+4877 ± 4calculated
Ta LIV53+5024 ± 5calculated
Ta LV54+5159 ± 5calculated
Ta LVI55+5537 ± 5calculated
Ta LVII56+5655 ± 5calculated
Ta LVIII57+5785 ± 6calculated
Ta LIX58+5907 ± 6calculated
Ta LX59+6364 ± 7calculated
Ta LXI60+6502 ± 10calculated
Ta LXII61+6769 ± 12calculated
Ta LXIII62+6900 ± 15calculated
Ta LXIV63+15137 ± 19calculated
Ta LXV64+15461 ± 24calculated
Ta LXVI65+15820 ± 30calculated
Ta LXVII66+16150 ± 40calculated
Ta LXVIII67+17840 ± 40calculated
Ta LXIX68+18250 ± 50calculated
Ta LXX69+18760 ± 50calculated
Ta LXXI70+19088.51 ± 0.19calculated
Ta LXXII71+76852 ± 0.17calculated
Ta LXXIII72+78394.63 ± 0.12calculated

Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.

Photos

Photo of the element: Tantalum (Ta)
© images-of-elements.com (CC BY 3.0)

Isotopes (40)

ANHalf-lifeDecay
Ta-155822.9 msp
Ta-15683106 msp
Ta-1578410.2 msα
Ta-1588549 msα
Ta-159861.04 sα
Ta-160871.55 sα
Ta-16188unknownα
Ta-162893.56 sEC/β⁺
Ta-1639010.7 sEC/β⁺
Ta-1649114.2 sEC/β⁺
Ta-1659231.0 sEC/β⁺
Ta-1669334.4 sEC/β⁺
Ta-1679480 sEC/β⁺
Ta-168952.0 minEC/β⁺
Ta-169964.9 minEC/β⁺
Ta-170976.76 minEC/β⁺
Ta-1719823.3 minEC/β⁺
Ta-1729936.8 minEC/β⁺
Ta-1731003.14 hEC/β⁺
Ta-1741011.08 hEC/β⁺
Ta-17510210.5 hEC/β⁺
Ta-1761038.08 hEC/β⁺
Ta-17710456.56 hEC/β⁺
Ta-1781052.41 hEC/β⁺
Ta-1791061.82 aEC
Ta-1801078.154 hEC
Ta-181108stable-
Ta-182109114.80 dβ⁻
Ta-1831105.1 dβ⁻
Ta-1841118.7 hβ⁻
Ta-18511249.5 minβ⁻
Ta-18611310.5 minβ⁻
Ta-187114283 sβ⁻
Ta-18811519.6 sβ⁻
Ta-189116unknownβ⁻
Ta-1901175.3 sβ⁻
Ta-191118unknownβ⁻
Ta-1921192.2 sβ⁻
Ta-193120unknownβ⁻
Ta-194121unknownβ⁻

Data sources

More about the data sources