Tantalum

Tantalum (Ta)

Heavy blue-grey metallic transition element. Ta-181 is a stable isotope, and Ta-180 is a radioactive isotope, with a half-life in excess of 10^7 years. Used in surgery as it is unreactive. Forms a passive oxide layer in air. Identified in 1802 by Ekeberg and isolated in 1820 by Jons J. Berzelius.
Atomic Number73
Atomic Weight180.94788
Mass Number181
Group5
Period6
Blockd
Protons73 p+
Neutrons108 n0
Electrons73 e-
Tantalum single crystal and 1cm3 cube.jpg Animated Bohr Model of Ta (Tantalum) Enhanced Bohr Model of Ta (Tantalum) Bohr Model: Ta (Tantalum) Orbital Diagram of Ta (Tantalum)

Properties

Atomic Radius
145 pm
Molar Volume
Covalent Radius
146 pm
Metallic Radius
134 pm
Ionic Radius
72 pm
Crystal Radius
86 pm
Van der Waals Radius
222 pm
Density
16.4 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy
7.54957 eV/particle
Heat of Vaporization
758 kJ/mol
Heat of Fusion
24.7 kJ/mol
Heat of Formation
782 kJ/mol
Electrons
Electron Shells2, 8, 18, 32, 11, 2
Valence Electrons5
Electron Configuration[Xe] 4f14 5d3 6s2
Oxidation States-3, -1, 0, 1, 2, 3, 4, 5
Electronegativity
1.5
Electrophilicity
1.0716190618855992 eV/particle
Phases
PhaseSolid
Gas Phase
Boiling Point
5,728.15 K
Melting Point
3,290.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Gray
Appearancegray blue
Refractive Index
Thermodynamic Properties
Thermal Conductivity
57.5 W/(m K)
Thermal Expansion
0.0000063 1/K
Molar Heat Capacity
25.36 J/(mol K)
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeConductor
Electrical Conductivity
7.7 MS/m
Electrical Resistivity
0.00000013 m Ω
Superconducting Point
4.47 K
Magnetism
Typeparamagnetic
Magnetic Susceptibility (Mass)
0.0000000107 m³/Kg
Magnetic Susceptibility (Molar)
0.000000001936 m³/mol
Magnetic Susceptibility (Volume)
0.0001782
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal StructureBody Centered Cubic (BCC)
Lattice Constant
3.31 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
6.5 MPa
Bulk Modulus
200 GPa
Shear Modulus
69 GPa
Young Modulus
186 GPa
Poisson Ratio
0.34
Speed of Sound
3,400 m/s
Classification
CategoryTransition metals, Transition metals
CAS GroupVA
IUPAC GroupVB
Glawe Number52
Mendeleev Number49
Pettifor Number53
Geochemical Classhigh field strength
Goldschmidt Classlitophile
Other
Gas Basicity
Dipole Polarizability
74 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
20.5
Neutron Mass Absorption
0.0041
Quantum Numbers4F3/2
Space Group229 (Im_3m)

Isotopes of Tantalum

Stable Isotopes1
Unstable Isotopes39
Radioactive Isotopes39

155Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
154.974248 ± 0.000322 Da
Mass Number155
G-Factor
Half Life
3.2 ± 1.3 ms
Spin11/2
Quadrupole Moment
Discovery Year2007
Parity-

155Ta Decay Modes
Decay ModeIntensity
p (proton emission)100%

156Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
155.972087 ± 0.000322 Da
Mass Number156
G-Factor
Half Life
106 ± 4 ms
Spin2
Quadrupole Moment
Discovery Year1992
Parity-

156Ta Decay Modes
Decay ModeIntensity
p (proton emission)71%
β+ (β+ decay; β+ = ϵ + e+)29%

157Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
156.968227445 ± 0.000161087 Da
Mass Number157
G-Factor
Half Life
10.1 ± 0.4 ms
Spin1/2
Quadrupole Moment
0
Discovery Year1979
Parity+

157Ta Decay Modes
Decay ModeIntensity
α (α emission)96.6%
p (proton emission)3.4%
β+ (β+ decay; β+ = ϵ + e+)%

158Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
157.966593 ± 0.000215 Da
Mass Number158
G-Factor
Half Life
49 ± 4 ms
Spin2
Quadrupole Moment
Discovery Year1979
Parity

158Ta Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

159Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
158.963028046 ± 0.000021137 Da
Mass Number159
G-Factor
Half Life
1.04 ± 0.09 s
Spin1/2
Quadrupole Moment
0
Discovery Year1979
Parity+

159Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)66%
α (α emission)34%

160Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
159.961541678 ± 0.00005831 Da
Mass Number160
G-Factor
Half Life
1.7 ± 0.2 s
Spin2
Quadrupole Moment
Discovery Year1979
Parity

160Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%
α (α emission)%

161Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
160.958369489 ± 0.000026174 Da
Mass Number161
G-Factor
Half Life
Spin1/2
Quadrupole Moment
0
Discovery Year1979
Parity+

161Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%
α (α emission)%

162Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
161.957292907 ± 0.000067979 Da
Mass Number162
G-Factor
Half Life
3.57 ± 0.12 s
Spin3
Quadrupole Moment
Discovery Year1985
Parity-

162Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)99.926%
α (α emission)0.074%

163Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
162.954337194 ± 0.00004086 Da
Mass Number163
G-Factor
Half Life
10.6 ± 1.8 s
Spin1/2
Quadrupole Moment
0
Discovery Year1985
Parity+

163Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)%

164Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
163.953534 ± 0.00003 Da
Mass Number164
G-Factor
Half Life
14.2 ± 0.3 s
Spin3
Quadrupole Moment
Discovery Year1982
Parity+

164Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

165Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
164.950780287 ± 0.000014571 Da
Mass Number165
G-Factor
Half Life
31 ± 1.5 s
Spin1/2
Quadrupole Moment
0
Discovery Year1982
Parity+

165Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

166Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
165.950512 ± 0.00003 Da
Mass Number166
G-Factor
Half Life
34.4 ± 0.5 s
Spin2
Quadrupole Moment
Discovery Year1977
Parity

166Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

167Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
166.948093 ± 0.00003 Da
Mass Number167
G-Factor
Half Life
1.33 ± 0.07 m
Spin3/2
Quadrupole Moment
Discovery Year1982
Parity+

167Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

168Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
167.948047 ± 0.00003 Da
Mass Number168
G-Factor
Half Life
2 ± 0.1 m
Spin3
Quadrupole Moment
Discovery Year1969
Parity+

168Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

169Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
168.946011 ± 0.00003 Da
Mass Number169
G-Factor
Half Life
4.9 ± 0.4 m
Spin5/2
Quadrupole Moment
Discovery Year1969
Parity+

169Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

170Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
169.946175 ± 0.00003 Da
Mass Number170
G-Factor
Half Life
6.76 ± 0.06 m
Spin3
Quadrupole Moment
Discovery Year1969
Parity+

170Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

171Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
170.944476 ± 0.00003 Da
Mass Number171
G-Factor
Half Life
23.3 ± 0.3 m
Spin5/2
Quadrupole Moment
Discovery Year1969
Parity+

171Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

172Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
171.944895 ± 0.00003 Da
Mass Number172
G-Factor
Half Life
36.8 ± 0.3 m
Spin3
Quadrupole Moment
Discovery Year1964
Parity+

172Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

173Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
172.94375 ± 0.00003 Da
Mass Number173
G-Factor
0.68 ± 0.012
Half Life
3.14 ± 0.13 h
Spin5/2
Quadrupole Moment
-1.8 ± 0.2
Discovery Year1960
Parity-

173Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

174Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
173.944454 ± 0.00003 Da
Mass Number174
G-Factor
Half Life
1.14 ± 0.08 h
Spin3
Quadrupole Moment
Discovery Year1960
Parity+

174Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

175Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
174.943737 ± 0.00003 Da
Mass Number175
G-Factor
0.64857142857143 ± 0.014285714285714
Half Life
10.5 ± 0.2 h
Spin7/2
Quadrupole Moment
3.5 ± 0.3
Discovery Year1960
Parity+

175Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

176Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
175.944857 ± 0.000033 Da
Mass Number176
G-Factor
Half Life
8.09 ± 0.05 h
Spin1
Quadrupole Moment
Discovery Year1948
Parity

176Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

177Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
176.94448194 ± 0.000003558 Da
Mass Number177
G-Factor
0.64285714285714 ± 0.014285714285714
Half Life
56.36 ± 0.13 h
Spin7/2
Quadrupole Moment
Discovery Year1948
Parity+

177Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

178Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
177.94568 ± 0.000056 Da
Mass Number178
G-Factor
Half Life
2.36 ± 0.08 h
Spin7
Quadrupole Moment
Discovery Year1950
Parity-

178Ta Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

179Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
178.94593905 ± 0.000001574 Da
Mass Number179
G-Factor
0.65314285714286 ± 0.0017142857142857
Half Life
1.82 ± 0.03 y
Spin7/2
Quadrupole Moment
3.27 ± 0.04
Discovery Year1950
Parity+

179Ta Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

180Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
179.947467589 ± 0.000002219 Da
Mass Number180
G-Factor
Half Life
8.154 ± 0.006 h
Spin1
Quadrupole Moment
Discovery Year1938
Parity+

180Ta Decay Modes
Decay ModeIntensity
ϵ (electron capture)85%
β (β decay)15%

181Ta

Abundance
99.98799 ± 0.00032
Relative Atomic Mass
180.947998528 ± 0.000001692 Da
Mass Number181
G-Factor
Half Life
Spin7/2
Quadrupole Moment
3.17 ± 0.02
Discovery Year1932
Parity+

182Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
181.950154612 ± 0.000001693 Da
Mass Number182
G-Factor
1.0066666666667 ± 0.01
Half Life
114.74 ± 0.12 d
Spin3
Quadrupole Moment
2.6 ± 0.3
Discovery Year1938
Parity-

182Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

183Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
182.95137538 ± 0.000001707 Da
Mass Number183
G-Factor
0.67428571428571 ± 0.0085714285714286
Half Life
5.1 ± 0.1 d
Spin7/2
Quadrupole Moment
Discovery Year1950
Parity+

183Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

184Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
183.954009958 ± 0.000027923 Da
Mass Number184
G-Factor
Half Life
8.7 ± 0.1 h
Spin5
Quadrupole Moment
Discovery Year1955
Parity-

184Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

185Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
184.955561317 ± 0.000015202 Da
Mass Number185
G-Factor
Half Life
49.4 ± 1.5 m
Spin7/2
Quadrupole Moment
Discovery Year1950
Parity+

185Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

186Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
185.958553036 ± 0.000064425 Da
Mass Number186
G-Factor
Half Life
10.5 ± 0.3 m
Spin3
Quadrupole Moment
Discovery Year1955
Parity

186Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

187Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
186.960391 ± 0.00006 Da
Mass Number187
G-Factor
Half Life
2.3 ± 6 m
Spin7/2
Quadrupole Moment
Discovery Year1999
Parity+

187Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

188Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
187.963596 ± 0.000215 Da
Mass Number188
G-Factor
Half Life
19.6 ± 2 s
Spin1
Quadrupole Moment
Discovery Year1999
Parity-

188Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

189Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
188.96569 ± 0.000215 Da
Mass Number189
G-Factor
Half Life
Spin7/2
Quadrupole Moment
Discovery Year1999
Parity+

189Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

190Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
189.969168 ± 0.000215 Da
Mass Number190
G-Factor
Half Life
5.3 ± 0.7 s
Spin3
Quadrupole Moment
Discovery Year2009
Parity

190Ta Decay Modes
Decay ModeIntensity
β (β decay)100%

191Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
190.97153 ± 0.000322 Da
Mass Number191
G-Factor
Half Life
Spin7/2
Quadrupole Moment
Discovery Year2009
Parity+

191Ta Decay Modes
Decay ModeIntensity
β (β decay)%

192Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
191.975201 ± 0.000429 Da
Mass Number192
G-Factor
Half Life
2.2 ± 0.7 s
Spin2
Quadrupole Moment
Discovery Year2009
Parity

192Ta Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

193Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
192.97766 ± 0.000429 Da
Mass Number193
G-Factor
Half Life
Spin7/2
Quadrupole Moment
Discovery Year2012
Parity+

193Ta Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%

194Ta

AbundanceRadioactive ☢️
Relative Atomic Mass
193.98161 ± 0.000537 Da
Mass Number194
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year2012
Parity

194Ta Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%

History

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

DiscoverersAnders Ekeberg
Discovery LocationSweden
Discovery Year1802
Etymology (Name Origin)From king Tantalus of Greek mythology, father of Niobe.
PronunciationTAN-te-lem (English)
Tantalum is considered to be non-toxic
Tantalum occurs principally in the mineral columbite-tantalite

Uses

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. Often used as an economical substitute for platinum. Tantalum pentoxide is used in capacitors and in camera lenses to increase refracting power. It and its alloys are corrosion and wear resistant so it is used to make surgical and dental tools.

Sources

Chiefly occurs in the mineral tantalite. Always found with niobium.

Abundance
Abundance in Earth's crust
Abundance in Oceans
0.000002 mg/L
Abundance in Human Body
Abundance in Meteor
0.000002 %
Abundance in Sun
Abundance in Universe
0.000000008 %

Nuclear Screening Constants

1s1.4163
2p4.4136
2s19.0702
3d13.5589
3p21.1996
3s21.9085
4d36.676
4f39.5296
4p34.2652
4s33.2412
5d56.632
5p52.5265
5s50.3065
6s63.475