Physics:Isotopes of tantalum

From HandWiki

Template:Infobox tantalum isotopes Natural tantalum (73Ta) consists of two stable isotopes: 181Ta (99.988%) and 180mTa (0.012%).

There are also 35 known artificial radioisotopes, the longest-lived of which are 179Ta with a half-life of 1.82 years, 182Ta with a half-life of 114.74 days, 183Ta with a half-life of 5.1 days, and 177Ta with a half-life of 56.46 hours. All other isotopes have half-lives under a day, most under an hour. There are also numerous isomers, the most stable of which (other than 180mTa) is 182m2Ta with a half-life of 15.8 minutes. All isotopes and nuclear isomers of tantalum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

Tantalum has been proposed as a "salting" material for nuclear weapons (cobalt is another, better-known salting material). A jacket of tantalum, irradiated by the intense high-energy neutron flux of the weapon, would be transmuted into the radioactive isotope The element Chemistry:Ta does not exist., producing about 1.12 MeV of gamma radiation per decay and significantly increasing the radioactivity of the weapon's fallout for months. Such a weapon is not known to have ever been built, tested, or used.[1]

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (u)
[n 2][n 3] 		Half-life
[n 4] 		Decay
mode
[n 5] 		Daughter
isotope
[n 6][n 7] 		Spin and
parity
[n 8][n 4] 		Physics:Natural abundance (mole fraction)
Excitation energy[n 4] Normal proportion Range of variation
155Ta 73 82 154.97425(32)# 2007 3.2(13) ms p 154Hf 11/2−
156Ta 73 83 155.97209(32)# 1992 106(4) ms p (71%) 155Hf (2−)
β+ (29%) 156Hf
156mTa 94(8) keV 1993 360(40) ms β+ (95.8%) 156Hf (9+)
p (4.2%) 155Hf
157Ta 73 84 156.96823(16) 1979 10.1(4) ms α (96.6%) 153Lu 1/2+
p (3.4%) 156Hf
157m1Ta 22(5) keV 1979 4.3(1) ms α 153Lu 11/2−
157m2Ta 1593(9) keV 1996 1.7(1) ms α 153Lu 25/2−#
158Ta 73 85 157.96659(22)# 1979 49(4) ms α 154Lu (2)−
158m1Ta 141(11) keV 1996 36.0(8) ms α (95%) 154Lu (9)+
158m2Ta 2808(16) keV 2014 6.1(1) μs IT (98.6%) 158Ta (19−)
α (1.4%) 154Lu
159Ta 73 86 158.963028(21) 1979 1.04(9) s β+ (66%) 159Hf 1/2+
α (34%) 155Lu
159mTa 64(5) keV 1979 560(60) ms α (55%) 155Lu 11/2−
β+ (45%) 159Hf
160Ta 73 87 159.961542(58) 1979 1.70(20) s α 156Lu (2)−
160mTa[n 9] 110(250) keV 1996 1.55(4) s α 156Lu (9,10)+
161Ta 73 88 160.958369(26) 1979 3# s (1/2+)
161mTa[n 9] 61(23) keV (2005)[n 10] 3.08(11) s β+ (93%) 161Hf (11/2−)
α (7%) 157Lu
162Ta 73 89 161.957293(68) 1985 3.57(12) s β+ (99.93%) 162Hf 3−#
α (0.074%) 158Lu
162mTa[n 9] 120(50)# keV (1974)[n 11] 5# s 7+#
163Ta 73 90 162.954337(41) 1985 10.6(18) s β+ (99.8%) 163Hf 1/2+
163mTa 138(18)# keV (1992)[n 11] 10# s 9/2−
164Ta 73 91 163.953534(30) 1982 14.2(3) s β+ 164Hf (3+)
165Ta 73 92 164.950780(15) 1982 31.0(15) s β+ 165Hf (1/2+,3/2+)
165mTa[n 9] 24(18) keV (1992)[n 11] 30# s (9/2−)
166Ta 73 93 165.950512(30) 1977 34.4(5) s β+ 166Hf (2)+
167Ta 73 94 166.948093(30) 1982 1.33(7) min β+ 167Hf (3/2+)
168Ta 73 95 167.948047(30) 1969 2.0(1) min β+ 168Hf (3+)
169Ta 73 96 168.946011(30) 1969 4.9(4) min β+ 169Hf (5/2+)
170Ta 73 97 169.946175(30) 1969 6.76(6) min β+ 170Hf (3+)
171Ta 73 98 170.944476(30) 1969 23.3(3) min β+ 171Hf (5/2+)
172Ta 73 99 171.944895(30) 1964 36.8(3) min β+ 172Hf (3+)
173Ta 73 100 172.943750(30) 1960 3.14(13) h β+ 173Hf 5/2−
173m1Ta 173.10(21) keV 1977 205.2(56) ns IT 173Ta 9/2−
173m2Ta 1717.2(4) keV 1977 132(3) ns IT 173Ta 21/2−
174Ta 73 101 173.944454(30) 1960 1.14(8) h β+ 174Hf 3+
175Ta 73 102 174.943737(30) 1960 10.5(2) h β+ 175Hf 7/2+
175m1Ta 131.41(17) keV 1972 222(8) ns IT 175Ta 9/2−
175m2Ta 339.2(13) keV (1969)[n 12] 170(20) ns IT 175Ta (1/2+)
175m3Ta 1567.6(3) keV 1972 1.95(15) μs IT 175Ta 21/2−
176Ta 73 103 175.944857(33) 1948 8.09(5) h β+ 176Hf (1)−
176m1Ta 103.0(10) keV 1971 1.08(7) ms IT 176Ta 7+
176m2Ta 1474.0(14) keV 1978 3.8(4) μs IT 176Ta 14−
176m3Ta 2874.0(14) keV 1994 0.97(7) ms IT 176Ta 20−
177Ta 73 104 176.9444819(36) 1948 56.36(13) h β+ 177Hf 7/2+
177m1Ta 73.16(7) keV 1973 410(7) ns IT 177Ta 9/2−
177m2Ta 186.16(6) keV 1970 3.62(10) μs IT 177Ta 5/2−
177m3Ta 1354.8(3) keV 1970 5.30(11) μs IT 177Ta 21/2−
177m4Ta 4656.3(8) keV 1994 133(4) μs IT 177Ta 49/2−
178Ta 73 105 177.945680(56)# 1950 2.36(8) h β+ 178Hf 7−
178m1Ta[n 9] 100(50)# keV 1950 9.31(3) min β+ 178Hf (1+)
178m2Ta 1467.82(16) keV 1979 59(3) ms IT 178Ta 15−
178m3Ta 2901.9(7) keV 1996 290(12) ms IT 178Ta 21−
179Ta 73 106 178.9459391(16) 1950 1.82(3) y EC 179Hf 7/2+
179m1Ta 30.7(1) keV 1964 1.42(8) μs IT 179Ta 9/2−
179m2Ta 520.23(18) keV 1974 280(80) ns IT 179Ta 1/2+
179m3Ta 1252.60(23) keV 1982 322(16) ns IT 179Ta 21/2−
179m4Ta 1317.2(4) keV 1982 9.0(2) ms IT 179Ta 25/2+
179m5Ta 1328.0(4) keV 1982 1.6(4) μs IT 179Ta 23/2−
179m6Ta 2639.3(5) keV 1982 54.1(17) ms IT 179Ta 37/2+
180Ta 73 107 179.9474676(22) 1938 8.154(6) h EC (85%) 180Hf 1+
β− (15%) 180W
180m1Ta 75.3(14) keV 1955 Observationally stable[n 13][n 14] 9− 1.201(32)×10−4
180m2Ta 1452.39(22) keV 1996 31.2(14) μs IT 15−
180m3Ta 3678.9(10) keV 2000 2.0(5) μs IT (22−)
180m4Ta 4172.2(16) keV 2000 17(5) μs IT (24+)
181Ta 73 108 180.9479985(17) 1932 Observationally stable[n 15] 7/2+ 0.9998799(32)
181m1Ta 6.237(20) keV 1961 6.05(12) μs IT 181Ta 9/2−
181m2Ta 615.19(3) keV 1946 18(1) μs IT 181Ta 1/2+
181m3Ta 1428(14) keV 1998 140(36) ns IT 181Ta 19/2+#
181m4Ta 1483.43(21) keV 1998 25.2(18) μs IT 181Ta 21/2−
181m5Ta 2227.9(9) keV 1998 210(20) μs IT 181Ta 29/2−
182Ta 73 109 181.9501546(17) 1938 114.74(12) d β− 182W 3−
182m1Ta 16.273(4) keV 1968 283(3) ms IT 182Ta 5+
182m2Ta 519.577(16) keV 1947 15.84(10) min IT 182Ta 10−
183Ta 73 110 182.9513754(17) 1950 5.1(1) d β− 183W 7/2+
183m1Ta 73.164(14) keV 1967 106(10) ns IT 183Ta 9/2−
183m2Ta 470(10)# keV 2026 42(5) μs IT 183Ta (1/2+)
183m3Ta 1335(14) keV 2009 0.9(3) μs IT 183Ta (19/2+)
184Ta 73 111 183.954010(28) 1955 8.7(1) h β− 184W (5−)
185Ta 73 112 184.955561(15) 1950 49.4(15) min β− 185W (7/2+)
185m1Ta 406(1) keV 2007 0.9(3) μs IT 185Ta (3/2+)
185m2Ta 1273.4(4) keV 1999 11.8(14) ms IT 185Ta 21/2−
186Ta 73 113 185.958553(64) 1955 10.5(3) min β− 186W 3#
186mTa 336(20) keV 2004 1.54(5) min 9+#
187Ta 73 114 186.960391(60) 1999 2.3(60) min β− 187W (7/2+)
187m1Ta 1778(1) keV 2010 7.3(9) s IT 187Ta (25/2−)
187m2Ta[3] 2933(14) keV 2010 136(24) s β− 187mW 41/2+#
[≥35/2]
IT 187m1Ta
188Ta 73 115 187.96360(22)# 1999 19.6(20) s β− 188W (1−)
188m1Ta 99(33) keV 2009 19.6(20) s (7−)
188m2Ta 391(33) keV 2005 3.6(4) μs IT 188Ta 10+#
189Ta 73 116 188.96569(22)# 1999 20# s [>300 ns] β− 189W 7/2+#
189mTa[4] 1309 keV 2009 1.20(7) μs IT 189Ta (19/2+)
189m2Ta 1444 keV 2025 160(20) ns IT 189Ta (21/2−)
190Ta 73 117 189.96917(22)# 2009 5.3(7) s β− 190W (3)
191Ta 73 118 190.97153(32)# 2009 460# ms [>300 ns] 7/2+#
192Ta 73 119 191.97520(43)# 2009 2.2(7) s β− 192W (2)
193Ta 73 120 192.97766(43)# 2012 220# ms [>300 ns] 7/2+#
194Ta 73 121 193.98161(54)# 2012 2# s [>300 ns]
  1. ↑ mTa – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ↑ 4.0 4.1 4.2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ↑ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition


    p: Proton emission
  6. ↑ Bold italics symbol as daughter – Daughter product is nearly stable.
  7. ↑ Bold symbol as daughter – Daughter product is stable.
  8. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 Order of ground state and isomer is uncertain.
  10. ↑ Only evidence for a different state from the ground state was reported in a conference proceeding, not included in the discovery data base.
  11. ↑ 11.0 11.1 11.2 Half-life not measured, not included in discovery database
  12. ↑ Only published in a conference proceeding and not a refereed journal
  13. ↑ Only known observationally stable nuclear isomer, believed to decay by isomeric transition to 180Ta, β− decay to 180W, or electron capture to 180Hf with a half-life over 2.9×1017 years;[2] also theorized to undergo α decay to 176Lu
  14. ↑ One of the few (observationally) stable odd-odd nuclei
  15. ↑ Believed to undergo α decay to 177Lu

Tantalum-180m

The nuclide The element Chemistry:Ta does not exist. (m denotes a metastable state) is one of a very few nuclear isomers which are more stable than their ground states. Although it is not unique in this regard (this property is shared by bismuth-210m (210mBi) and americium-242m (242mAm), among other nuclides), it is exceptional in that it is observationally stable: no decay has ever been observed. In contrast, the ground state nuclide The element Chemistry:Ta does not exist. has a half-life of only 8 hours.The element Chemistry:Ta does not exist. has sufficient energy to decay in three ways: isomeric transition to the ground state of The element Chemistry:Ta does not exist., beta decay to [[Tungsten|The element Chemistry:W does not exist.]], or electron capture to [[Hafnium|The element Chemistry:Hf does not exist.]]. However, no radioactivity from any of these theoretically possible decay modes has ever been observed. As of 2023, the half-life of 180mTa is calculated from experimental observation to be at least 2.9×1017 (290 quadrillion) years.[2][5][6] The very slow decay of The element Chemistry:Ta does not exist. is attributed to its high spin (9 units) and the low spin of lower-lying states. Gamma or beta decay would require many units of angular momentum to be removed in a single step, so that the process would be very slow.[7] Similar suppression of gamma or beta decay occurs for 210mBi, a rather short-lived alpha emitter.[8]

Because of this stability, The element Chemistry:Ta does not exist. is a primordial nuclide, the only naturally occurring nuclear isomer (excluding short-lived radiogenic and cosmogenic nuclides). It presents one of two apparent violations of the Mattauch isobar rule, the other involving tellurium-123. It is also the rarest primordial nuclide in the Universe observed for any element which has any stable isotopes. In an s-process stellar environment with a thermal energy kBT = 26 keV (i.e. a temperature of 300 million kelvin), the nuclear isomers are expected to be fully thermalized, meaning that 180Ta is equilibrated between spin states and its overall half-life is predicted to be 11 hours.[9]

It is one of only five stable nuclides to have both an odd number of protons and an odd number of neutrons, the other four stable odd-odd nuclides being 2H, 6Li, 10B and 14N.[10]

See also

Daughter products other than tantalum

References

  1. ↑ D. T. Win; M. Al Masum (2003). "Weapons of Mass Destruction". Assumption University Journal of Technology 6 (4): 199–219. http://www.journal.au.edu/au_techno/2003/apr2003/aujt6-4_article07.pdf. Retrieved 2015-09-24. 
  2. ↑ 2.0 2.1 Arnquist, I. J.; Avignone III, F. T.; Barabash, A. S.; Barton, C. J.; Bhimani, K. H.; Blalock, E.; Bos, B.; Busch, M. et al. (13 October 2023). "Constraints on the Decay of 180mTa". Phys. Rev. Lett. 131 (15). doi:10.1103/PhysRevLett.131.152501. PMID 37897780. 
  3. ↑ Chen, J. L.Expression error: Unrecognized word "et". (2025). "Direct observation of β and γ decay from a high-spin long-lived isomer in 187Ta". Physical Review C 111 (14304). doi:10.1103/PhysRevC.111.014304. 
  4. ↑ {{cite |DOI: https://doi.org/10.1103/PhysRevC.111.L031301
  5. ↑ Conover, Emily (2016-10-03). "Rarest nucleus reluctant to decay". Science News. https://www.sciencenews.org/article/rarest-nucleus-reluctant-decay. 
  6. ↑ Lehnert, Björn; Hult, Mikael; Lutter, Guillaume; Zuber, Kai (2017). "Search for the decay of nature's rarest isotope 180mTa". Physical Review C 95 (4). doi:10.1103/PhysRevC.95.044306. Bibcode: 2017PhRvC..95d4306L. 
  7. ↑ Quantum mechanics for engineers Leon van Dommelen, Florida State University
  8. ↑ Tuggle, D. G. (August 1976). Decay studies of a long lived high spin isomer of 210Bi (Thesis). California Univ., Berkeley (USA): Lawrence Berkeley Lab. See the section "210mBi Decay to 210Po".
  9. ↑ P. Mohr; F. Kaeppeler; R. Gallino (2007). "Survival of Nature's Rarest Isotope 180Ta under Stellar Conditions". Phys. Rev. C 75. doi:10.1103/PhysRevC.75.012802. 
  10. ↑ Lide, David R., ed (2002). Handbook of Chemistry & Physics (88th ed.). CRC. ISBN 978-0-8493-0486-6. OCLC 179976746. http://www.hbcpnetbase.com/. Retrieved 2008-05-23. 

Lua error: Internal error: The interpreter has terminated with signal "24".


Lua error: Internal error: The interpreter has terminated with signal "24".


Retrieved from "https://handwiki.org/wiki/index.php?title=Physics:Isotopes_of_tantalum&oldid=4368268"