View source for Physics:Isotopes of tantalum

{{Short description|List of nuclides having atomic number 73 but different mass numbers}}
Natural [[Chemistry:Tantalum|tantalum]] (<sub>73</sub>Ta) consists of two stable [[Physics:Isotope|isotope]]s: <sup>181</sup>Ta (99.988%) and {{SimpleNuclide|Ta|180|m}} (0.012%).

There are also 35 known artificial radioisotopes, the longest-lived of which are <sup>179</sup>Ta with a half-life of 1.82 years, <sup>182</sup>Ta with a half-life of 114.43 days, <sup>183</sup>Ta with a half-life of 5.1 days, and <sup>177</sup>Ta with a half-life of 56.56 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 <sup>180m</sup>Ta) is <sup>178m1</sup>Ta with a half-life of 2.36 hours. 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 [[Engineering:Nuclear weapon|nuclear weapon]]s ([[Chemistry:Cobalt|cobalt]] is another, better-known salting material). A jacket of <sup>181</sup>Ta, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope {{SimpleNuclide|Ta|182}} with a [[Physics:Half-life|half-life]] of 114.43 days and produce approximately 1.12&nbsp;[[Physics:MeV|MeV]] of [[Physics:Gamma ray|gamma radiation]], significantly increasing the radioactivity of the weapon's [[Physics:Nuclear fallout|fallout]] for several months. Such a weapon is not known to have ever been built, tested, or used.<ref>{{cite journal
 | author = D. T. Win |author2=M. Al Masum
 | year = 2003
 | title = Weapons of Mass Destruction
 | url = http://www.journal.au.edu/au_techno/2003/apr2003/aujt6-4_article07.pdf
 | journal=Assumption University Journal of Technology
 | volume = 6 | issue =4 | pages = 199&ndash;219
}}</ref> While the conversion factor from [[Physics:Absorbed dose|absorbed dose]] (measured in [[Physics:Gray (unit)|Grays]]) to [[Physics:Effective dose (radiation)|effective dose]] (measured in Sievert) for gamma rays is 1 while it is 50 for alpha radiation (i.e., a gamma dose of 1 Gray is equivalent to 1 Sievert whereas an alpha dose of 1 Gray is equivalent to 50 Sievert), gamma rays are only [[Physics:Attenuation|attenuated]] by shielding, not stopped. As such, alpha particles require incorporation to have an effect while gamma rays can have an effect via mere proximity. In military terms, this allows a gamma ray weapon to deny an area to either side as long as the dose is high enough, whereas [[Physics:Radioactive contamination|radioactive contamination]] by alpha emitters which do not release significant amounts of gamma rays can be counteracted by ensuring the material is not incorporated.

== List of isotopes ==
{{Isotopes table
|symbol=Ta
|refs=<!-- not NUBASE2016 yet (2019-07-14) -->
|notes=m, unc(), mass#, exen#, hl#, spin(), spin#, daughter-st, daughter-nst, p, IT, EC, 
}}
|-
| {{SimpleNuclide|Ta|155}}
| style="text-align:right" | 73
| style="text-align:right" | 82
| 154.97459(54)#
| {{val|2.9|1.5|1.1|u=ms}}<ref>{{cite journal |last1=Page |first1=R. D. |last2=Bianco |first2=L. |last3=Darby |first3=I. G. |last4=Uusitalo |first4=J. |last5=Joss |first5=D. T. |last6=Grahn |first6=T. |last7=Herzberg |first7=R.-D. |last8=Pakarinen |first8=J. |last9=Thomson |first9=J. |last10=Eeckhaudt |first10=S. |last11=Greenlees |first11=P. T. |last12=Jones |first12=P. M. |last13=Julin |first13=R. |last14=Juutinen |first14=S. |last15=Ketelhut |first15=S. |last16=Leino |first16=M. |last17=Leppänen |first17=A.-P. |last18=Nyman |first18=M. |last19=Rahkila |first19=P. |last20=Sarén |first20=J. |last21=Scholey |first21=C. |last22=Steer |first22=A. |last23=Hornillos |first23=M. B. Gómez |last24=Al-Khalili |first24=J. S. |last25=Cannon |first25=A. J. |last26=Stevenson |first26=P. D. |last27=Ertürk |first27=S. |last28=Gall |first28=B. |last29=Hadinia |first29=B. |last30=Venhart |first30=M. |last31=Simpson |first31=J. |title=α decay of Re 159 and proton emission from Ta 155 |journal=Physical Review C |date=26 June 2007 |volume=75 |issue=6 |page=061302 |doi=10.1103/PhysRevC.75.061302 |bibcode=2007PhRvC..75f1302P |language=en |issn=0556-2813|url=https://openresearch.surrey.ac.uk/view/delivery/44SUR_INST/12139605080002346/13140305300002346 }}</ref>
| [[Physics:Proton emission|p]]
| <sup>154</sup>Hf
| (11/2−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|155|m}}
| colspan="3" style="text-indent:2em" | ~323 keV
| {{val|12|4|3|u=μs}}<ref>{{cite journal |last1=Uusitalo |first1=J. |last2=Davids |first2=C. N. |last3=Woods |first3=P. J. |last4=Seweryniak |first4=D. |last5=Sonzogni |first5=A. A. |last6=Batchelder |first6=J. C. |last7=Bingham |first7=C. R. |last8=Davinson |first8=T. |last9=deBoer |first9=J. |last10=Henderson |first10=D. J. |last11=Maier |first11=H. J. |last12=Ressler |first12=J. J. |last13=Slinger |first13=R. |last14=Walters |first14=W. B. |title=Proton emission from the closed neutron shell nucleus 155 Ta |journal=Physical Review C |date=1 June 1999 |volume=59 |issue=6 |pages=R2975–R2978 |doi=10.1103/PhysRevC.59.R2975 |bibcode=1999PhRvC..59.2975U |url=https://journals.aps.org/prc/pdf/10.1103/PhysRevC.59.R2975 |access-date=12 June 2023 |language=en |issn=0556-2813}}</ref>
| p
| <sup>154</sup>Hf
| 11/2−?
|
|
|-
| rowspan=2|{{SimpleNuclide|Ta|156}}<ref>{{cite journal |last1=Darby |first1=I. G. |last2=Page |first2=R. D. |last3=Joss |first3=D. T. |last4=Bianco |first4=L. |last5=Grahn |first5=T. |last6=Judson |first6=D. S. |last7=Simpson |first7=J. |last8=Eeckhaudt |first8=S. |last9=Greenlees |first9=P. T. |last10=Jones |first10=P. M. |last11=Julin |first11=R. |last12=Juutinen |first12=S. |last13=Ketelhut |first13=S. |last14=Leino |first14=M. |last15=Leppänen |first15=A.-P. |last16=Nyman |first16=M. |last17=Rahkila |first17=P. |last18=Sarén |first18=J. |last19=Scholey |first19=C. |last20=Steer |first20=A. N. |last21=Uusitalo |first21=J. |last22=Venhart |first22=M. |last23=Ertürk |first23=S. |last24=Gall |first24=B. |last25=Hadinia |first25=B. |title=Precision measurements of proton emission from the ground states of Ta 156 and Re 160 |journal=Physical Review C |date=20 June 2011 |volume=83 |issue=6 |page=064320 |doi=10.1103/PhysRevC.83.064320 |bibcode=2011PhRvC..83f4320D |url=https://journals.aps.org/prc/pdf/10.1103/PhysRevC.83.064320 |access-date=21 June 2023 |language=en |issn=0556-2813}}</ref>
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 83
| rowspan=2|155.97230(43)#
| rowspan=2|106(4)&nbsp;ms
| p (71%)
| <sup>155</sup>Hf
| rowspan=2|(2−)
| rowspan=2|
| rowspan=2|
|-
| [[Physics:Beta decay|β<sup>+</sup>]] (29%)
| <sup>156</sup>Hf
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|156|m}}
| colspan="3" style="text-indent:2em" | 102(7)&nbsp;keV
| 0.36(4)&nbsp;s
| p
| <sup>155</sup>Hf
| 9+
|
|
|-
| rowspan=2|{{SimpleNuclide|Ta|157}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 84
| rowspan=2|156.96819(22)
| rowspan=2|10.1(4)&nbsp;ms
| [[Physics:Alpha decay|α]] (91%)
| <sup>153</sup>Lu
| rowspan=2|1/2+
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (9%)
| <sup>157</sup>Hf
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|157|m1}}
| colspan="3" style="text-indent:2em" | 22(5)&nbsp;keV
| 4.3(1)&nbsp;ms
|
|
| 11/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|157|m2}}
| colspan="3" style="text-indent:2em" | 1593(9)&nbsp;keV
| 1.7(1)&nbsp;ms
| α
| <sup>153</sup>Lu
| (25/2−)
|
|
|-
| rowspan=2|{{SimpleNuclide|Ta|158}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 85
| rowspan=2|157.96670(22)#
| rowspan=2|49(8)&nbsp;ms
| α (96%)
| <sup>154</sup>Lu
| rowspan=2|(2−)
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (4%)
| <sup>158</sup>Hf
|-
| rowspan=3 style="text-indent:1em" | {{SimpleNuclide|Ta|158|m}}
| rowspan=3 colspan="3" style="text-indent:2em" | 141(9)&nbsp;keV
| rowspan=3|36.0(8)&nbsp;ms
| α (93%)
| <sup>154</sup>Lu
| rowspan=3|(9+)
| rowspan=3|
| rowspan=3|
|-
| IT
| <sup>158</sup>Ta
|-
| β<sup>+</sup>
| <sup>158</sup>Hf
|-
| rowspan=2|{{SimpleNuclide|Ta|159}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 86
| rowspan=2|158.963018(22)
| rowspan=2|1.04(9)&nbsp;s
| β<sup>+</sup> (66%)
| <sup>159</sup>Hf
| rowspan=2|(1/2+)
| rowspan=2|
| rowspan=2|
|-
| α (34%)
| <sup>155</sup>Lu
|-
| rowspan=2 style="text-indent:1em" | {{SimpleNuclide|Ta|159|m}}
| rowspan=2 colspan="3" style="text-indent:2em" | 64(5)&nbsp;keV
| rowspan=2|514(9)&nbsp;ms
| α (56%)
| <sup>155</sup>Lu
| rowspan=2|(11/2−)
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (44%)
| <sup>159</sup>Hf
|-
| rowspan=2|{{SimpleNuclide|Ta|160}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 87
| rowspan=2|159.96149(10)
| rowspan=2|1.70(20)&nbsp;s
| α
| <sup>156</sup>Lu
| rowspan=2|(2#)−
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup>
| <sup>160</sup>Hf
|-
| rowspan=2 style="text-indent:1em" | {{SimpleNuclide|Ta|160|m}}
| rowspan=2 colspan="3" style="text-indent:2em" | 310(90)#&nbsp;keV
| rowspan=2|1.55(4)&nbsp;s
| β<sup>+</sup> (66%)
| <sup>160</sup>Hf
| rowspan=2|(9)+
| rowspan=2|
| rowspan=2|
|-
| α (34%)
| <sup>156</sup>Lu
|-
| rowspan=2|{{SimpleNuclide|Ta|161}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 88
| rowspan=2|160.95842(6)#
| rowspan=2|3# s
| β<sup>+</sup> (95%)
| <sup>161</sup>Hf
| rowspan=2|1/2+#
| rowspan=2|
| rowspan=2|
|-
| α (5%)
| <sup>157</sup>Lu
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|161|m}}
| colspan="3" style="text-indent:2em" | 50(50)#&nbsp;keV
| 2.89(12)&nbsp;s
|
|
| 11/2−#
|
|
|-
| rowspan=2|{{SimpleNuclide|Ta|162}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 89
| rowspan=2|161.95729(6)
| rowspan=2|3.57(12)&nbsp;s
| β<sup>+</sup> (99.92%)
| <sup>162</sup>Hf
| rowspan=2|3+#
| rowspan=2|
| rowspan=2|
|-
| α (.073%)
| <sup>158</sup>Lu
|-
| rowspan=2|{{SimpleNuclide|Ta|163}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 90
| rowspan=2|162.95433(4)
| rowspan=2|10.6(18)&nbsp;s
| β<sup>+</sup> (99.8%)
| <sup>163</sup>Hf
| rowspan=2|1/2+#
| rowspan=2|
| rowspan=2|
|-
| α (.2%)
| <sup>159</sup>Lu
|-
| {{SimpleNuclide|Ta|164}}
| style="text-align:right" | 73
| style="text-align:right" | 91
| 163.95353(3)
| 14.2(3)&nbsp;s
| β<sup>+</sup>
| <sup>164</sup>Hf
| (3+)
|
|
|-
| {{SimpleNuclide|Ta|165}}
| style="text-align:right" | 73
| style="text-align:right" | 92
| 164.950773(19)
| 31.0(15)&nbsp;s
| β<sup>+</sup>
| <sup>165</sup>Hf
| 5/2−#
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|165|m}}
| colspan="3" style="text-indent:2em" | 60(30)&nbsp;keV
|
|
|
| 9/2−#
|
|
|-
| {{SimpleNuclide|Ta|166}}
| style="text-align:right" | 73
| style="text-align:right" | 93
| 165.95051(3)
| 34.4(5)&nbsp;s
| β<sup>+</sup>
| <sup>166</sup>Hf
| (2)+
|
|
|-
| {{SimpleNuclide|Ta|167}}
| style="text-align:right" | 73
| style="text-align:right" | 94
| 166.94809(3)
| 1.33(7)&nbsp;min
| β<sup>+</sup>
| <sup>167</sup>Hf
| (3/2+)
|
|
|-
| {{SimpleNuclide|Ta|168}}
| style="text-align:right" | 73
| style="text-align:right" | 95
| 167.94805(3)
| 2.0(1)&nbsp;min
| β<sup>+</sup>
| <sup>168</sup>Hf
| (2−,3+)
|
|
|-
| {{SimpleNuclide|Ta|169}}
| style="text-align:right" | 73
| style="text-align:right" | 96
| 168.94601(3)
| 4.9(4)&nbsp;min
| β<sup>+</sup>
| <sup>169</sup>Hf
| (5/2+)
|
|
|-
| {{SimpleNuclide|Ta|170}}
| style="text-align:right" | 73
| style="text-align:right" | 97
| 169.94618(3)
| 6.76(6)&nbsp;min
| β<sup>+</sup>
| <sup>170</sup>Hf
| (3)(+#)
|
|
|-
| {{SimpleNuclide|Ta|171}}
| style="text-align:right" | 73
| style="text-align:right" | 98
| 170.94448(3)
| 23.3(3)&nbsp;min
| β<sup>+</sup>
| <sup>171</sup>Hf
| (5/2−)
|
|
|-
| {{SimpleNuclide|Ta|172}}
| style="text-align:right" | 73
| style="text-align:right" | 99
| 171.94490(3)
| 36.8(3)&nbsp;min
| β<sup>+</sup>
| <sup>172</sup>Hf
| (3+)
|
|
|-
| {{SimpleNuclide|Ta|173}}
| style="text-align:right" | 73
| style="text-align:right" | 100
| 172.94375(3)
| 3.14(13)&nbsp;h
| β<sup>+</sup>
| <sup>173</sup>Hf
| 5/2−
|
|
|-
| {{SimpleNuclide|Ta|174}}
| style="text-align:right" | 73
| style="text-align:right" | 101
| 173.94445(3)
| 1.14(8)&nbsp;h
| β<sup>+</sup>
| '''''<sup>174</sup>Hf'''''
| 3+
|
|
|-
| {{SimpleNuclide|Ta|175}}
| style="text-align:right" | 73
| style="text-align:right" | 102
| 174.94374(3)
| 10.5(2)&nbsp;h
| β<sup>+</sup>
| <sup>175</sup>Hf
| 7/2+
|
|
|-
| {{SimpleNuclide|Ta|176}}
| style="text-align:right" | 73
| style="text-align:right" | 103
| 175.94486(3)
| 8.09(5)&nbsp;h
| β<sup>+</sup>
| '''<sup>176</sup>Hf'''
| (1)−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|176|m1}}
| colspan="3" style="text-indent:2em" | 103.0(10)&nbsp;keV
| 1.1(1)&nbsp;ms
| IT
| <sup>176</sup>Ta
| (+)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|176|m2}}
| colspan="3" style="text-indent:2em" | 1372.6(11)+X&nbsp;keV
| 3.8(4)&nbsp;µs
|
|
| (14−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|176|m3}}
| colspan="3" style="text-indent:2em" | 2820(50)&nbsp;keV
| 0.97(7)&nbsp;ms
|
|
| (20−)
|
|
|-
| {{SimpleNuclide|Ta|177}}
| style="text-align:right" | 73
| style="text-align:right" | 104
| 176.944472(4)
| 56.56(6)&nbsp;h
| β<sup>+</sup>
| '''<sup>177</sup>Hf'''
| 7/2+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|177|m1}}
| colspan="3" style="text-indent:2em" | 73.36(15)&nbsp;keV
| 410(7)&nbsp;ns
|
|
| 9/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|177|m2}}
| colspan="3" style="text-indent:2em" | 186.15(6)&nbsp;keV
| 3.62(10)&nbsp;µs
|
|
| 5/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|177|m3}}
| colspan="3" style="text-indent:2em" | 1355.01(19)&nbsp;keV
| 5.31(25)&nbsp;µs
|
|
| 21/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|177|m4}}
| colspan="3" style="text-indent:2em" | 4656.3(5)&nbsp;keV
| 133(4)&nbsp;µs
|
|
| 49/2−
|
|
|-
| {{SimpleNuclide|Ta|178}}
| style="text-align:right" | 73
| style="text-align:right" | 105
| 177.945778(16)
| 9.31(3)&nbsp;min
| β<sup>+</sup>
| '''<sup>178</sup>Hf'''
| 1+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|178|m1}}
| colspan="3" style="text-indent:2em" | 100(50)#&nbsp;keV
| 2.36(8)&nbsp;h
| β<sup>+</sup>
| '''<sup>178</sup>Hf'''
| (7)−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|178|m2}}
| colspan="3" style="text-indent:2em" | 1570(50)#&nbsp;keV
| 59(3)&nbsp;ms
|
|
| (15−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|178|m3}}
| colspan="3" style="text-indent:2em" | 3000(50)#&nbsp;keV
| 290(12)&nbsp;ms
|
|
| (21−)
|
|
|-
| {{SimpleNuclide|Ta|179}}
| style="text-align:right" | 73
| style="text-align:right" | 106
| 178.9459295(23)
| 1.82(3) y
| [[Physics:Electron capture|EC]]
| '''<sup>179</sup>Hf'''
| 7/2+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m1}}
| colspan="3" style="text-indent:2em" | 30.7(1)&nbsp;keV
| 1.42(8)&nbsp;µs
|
|
| (9/2)−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m2}}
| colspan="3" style="text-indent:2em" | 520.23(18)&nbsp;keV
| 335(45)&nbsp;ns
|
|
| (1/2)+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m3}}
| colspan="3" style="text-indent:2em" | 1252.61(23)&nbsp;keV
| 322(16)&nbsp;ns
|
|
| (21/2−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m4}}
| colspan="3" style="text-indent:2em" | 1317.3(4)&nbsp;keV
| 9.0(2)&nbsp;ms
| IT
| <sup>179</sup>Ta
| (25/2+)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m5}}
| colspan="3" style="text-indent:2em" | 1327.9(4)&nbsp;keV
| 1.6(4)&nbsp;µs
|
|
| (23/2−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|179|m6}}
| colspan="3" style="text-indent:2em" | 2639.3(5)&nbsp;keV
| 54.1(17)&nbsp;ms
|
|
| (37/2+)
|
|
|-
| rowspan=2|{{SimpleNuclide|Ta|180}}
| rowspan=2 style="text-align:right" | 73
| rowspan=2 style="text-align:right" | 107
| rowspan=2|179.9474648(24)
| rowspan=2|8.152(6)&nbsp;h
| EC (86%)
| '''<sup>180</sup>Hf'''
| rowspan=2|1+
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup> (14%)
| '''''<sup>180</sup>W'''''
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|180|m1}}
| colspan="3" style="text-indent:2em" | 77.1(8)&nbsp;keV
| colspan=3 align=center|'''Observationally stable'''{{r|g=n|r=Only known observationally stable nuclear isomer, believed to decay by isomeric transition to <sup>180</sup>Ta, β<sup>−</sup> decay to '''''<sup>180</sup>W''''', or electron capture to '''<sup>180</sup>Hf''' with a half-life over 2.9×10<sup>17</sup> years<ref name="180mTa_2023"/>; also theorized to undergo α decay to '''''<sup>176</sup>Lu'''''}}<ref group="n">One of the few (observationally) stable [[Physics:Even and odd atomic nuclei#Odd proton, odd neutron|odd-odd nuclei]]</ref>
| 9−
| 1.2(2)×10<sup>−4</sup>
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|180|m2}}
| colspan="3" style="text-indent:2em" | 1452.40(18)&nbsp;keV
| 31.2(14)&nbsp;µs
|
|
| 15−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|180|m3}}
| colspan="3" style="text-indent:2em" | 3679.0(11)&nbsp;keV
| 2.0(5)&nbsp;µs
|
|
| (22−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|180|m4}}
| colspan="3" style="text-indent:2em" | 4171.0+X&nbsp;keV
| 17(5)&nbsp;µs
|
|
| (23, 24, 25)
|
|
|-
| {{SimpleNuclide|Ta|181}}
| style="text-align:right" | 73
| style="text-align:right" | 108
| 180.9479958(20)
| colspan=3 align=center|'''Observationally stable'''<ref group="n">Believed to undergo α decay to <sup>177</sup>Lu</ref>
| 7/2+
| 0.99988(2)
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|181|m1}}
| colspan="3" style="text-indent:2em" | 6.238(20)&nbsp;keV
| 6.05(12)&nbsp;µs
|
|
| 9/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|181|m2}}
| colspan="3" style="text-indent:2em" | 615.21(3)&nbsp;keV
| 18(1)&nbsp;µs
|
|
| 1/2+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|181|m3}}
| colspan="3" style="text-indent:2em" | 1485(3)&nbsp;keV
| 25(2)&nbsp;µs
|
|
| 21/2−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|181|m4}}
| colspan="3" style="text-indent:2em" | 2230(3)&nbsp;keV
| 210(20)&nbsp;µs
|
|
| 29/2−
|
|
|-
| {{SimpleNuclide|Ta|182}}
| style="text-align:right" | 73
| style="text-align:right" | 109
| 181.9501518(19)
| 114.43(3)&nbsp;d
| β<sup>−</sup>
| '''<sup>182</sup>W'''
| 3−
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|182|m1}}
| colspan="3" style="text-indent:2em" | 16.263(3)&nbsp;keV
| 283(3)&nbsp;ms
| IT
| <sup>182</sup>Ta
| 5+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|182|m2}}
| colspan="3" style="text-indent:2em" | 519.572(18)&nbsp;keV
| 15.84(10)&nbsp;min
|
|
| 10−
|
|
|-
| {{SimpleNuclide|Ta|183}}
| style="text-align:right" | 73
| style="text-align:right" | 110
| 182.9513726(19)
| 5.1(1)&nbsp;d
| β<sup>−</sup>
| '''<sup>183</sup>W'''
| 7/2+
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|183|m}}
| colspan="3" style="text-indent:2em" | 73.174(12)&nbsp;keV
| 107(11)&nbsp;ns
|
|
| 9/2−
|
|
|-
| {{SimpleNuclide|Ta|184}}
| style="text-align:right" | 73
| style="text-align:right" | 111
| 183.954008(28)
| 8.7(1)&nbsp;h
| β<sup>−</sup>
| '''<sup>184</sup>W'''
| (5−)
|
|
|-
| {{SimpleNuclide|Ta|185}}
| style="text-align:right" | 73
| style="text-align:right" | 112
| 184.955559(15)
| 49.4(15)&nbsp;min
| β<sup>−</sup>
| <sup>185</sup>W
| (7/2+)#
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|185|m}}
| colspan="3" style="text-indent:2em" | 1308(29)&nbsp;keV
| >1&nbsp;ms
|
|
| (21/2−)
|
|
|-
| {{SimpleNuclide|Ta|186}}
| style="text-align:right" | 73
| style="text-align:right" | 113
| 185.95855(6)
| 10.5(3)&nbsp;min
| β<sup>−</sup>
| '''<sup>186</sup>W'''
| (2−,3−)
|
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Ta|186|m}}
| colspan="3" style="text-indent:2em" |
| 1.54(5)&nbsp;min
|
|
|
|
|
|-
| {{SimpleNuclide|Ta|187}}
| style="text-align:right" | 73
| style="text-align:right" | 114
| 186.96053(21)#
| 2#&nbsp;min<br>[>300&nbsp;ns]
| β<sup>−</sup>
| <sup>187</sup>W
| 7/2+#
|
|
|-
| {{SimpleNuclide|Ta|188}}
| style="text-align:right" | 73
| style="text-align:right" | 115
| 187.96370(21)#
| 20# s<br>[>300&nbsp;ns]
| β<sup>−</sup>
| <sup>188</sup>W
|
|
|
|-
| {{SimpleNuclide|Ta|189}}
| style="text-align:right" | 73
| style="text-align:right" | 116
| 188.96583(32)#
| 3# s<br>[>300&nbsp;ns]
|
|
| 7/2+#
|
|
|-
| {{SimpleNuclide|Ta|190}}
| style="text-align:right" | 73
| style="text-align:right" | 117
| 189.96923(43)#
| 0.3# s
|
|
|
|
|
{{Isotopes table/footer}}

== Tantalum-180m ==
The nuclide {{SimpleNuclide|Ta|180|m}} (''m'' denotes a metastable state) has sufficient energy to decay in three ways: isomeric transition to the [[Physics:Ground state|ground state]] of {{SimpleNuclide|Ta|180}}, [[Physics:Beta decay|beta decay]] to [[Chemistry:Tungsten|{{SimpleNuclide|W|180}}]], and [[Physics:Electron capture|electron capture]] to [[Chemistry:Hafnium|{{SimpleNuclide|Hf|180}}]]. However, no radioactivity from any decay mode of this [[Physics:Nuclear isomer|nuclear isomer]] has ever been observed. As of 2023, the half-life of <sup>180m</sup>Ta is calculated from experimental observation to be at least {{val|2.9|e=17}} (290 quadrillion) years.<ref name="180mTa_2023">{{Cite journal|last1=Arnquist|first1=I. J.|last2=Avignone III|first2=F. T.|last3=Barabash|first3=A. S.|last4=Barton|first4=C. J.|last5=Bhimani|first5=K. H.|last6=Blalock|first6=E.|last7=Bos|first7=B.|last8=Busch|first8=M.|last9=Buuck|first9=M.|last10=Caldwell|first10=T. S.|last11=Christofferson|first11=C. D.|last12=Chu|first12=P.-H.|last13=Clark|first13=M. L.|last14=Cuesta|first14=C.|last15=Detwiler|first15=J. A.|last16=Efremenko|first16=Yu.|last17=Ejiri|first17=H.|last18=Elliott|first18=S. R.|last19=Giovanetti|first19=G. K.|last20=Goett|first20=J.|last21=Green|first21=M. P.|last22=Gruszko|first22=J.|last23=Guinn|first23=I. S.|last24=Guiseppe|first24=V. E.|last25=Haufe|first25=C. R.|last26=Henning|first26=R.|last27=Aguilar|first27=D. Hervas|last28=Hoppe|first28=E. W.|last29=Hostiuc|first29=A.|last30=Kim|first30=I.|last31=Kouzes|first31=R. T.|last32=Lannen V.|first32=T. E.|last33=Li|first33=A.|last34=López-Castaño|first34=J. M.|last35=Massarczyk|first35=R.|last36=Meijer|first36=S. J.|last37=Meijer|first37=W.|last38=Oli|first38=T. K.|last39=Paudel|first39=L. S.|last40=Pettus|first40=W.|last41=Poon|first41=A. W. P.|last42=Radford|first42=D. C.|last43=Reine|first43=A. L.|last44=Rielage|first44=K.|last45=Rouyer|first45=A.|last46=Ruof|first46=N. W.|last47=Schaper|first47=D. C.|last48=Schleich|first48=S. J.|last49=Smith-Gandy|first49=T. A.|last50=Tedeschi|first50=D.|last51=Thompson|first51=J. D.|last52=Varner|first52=R. L.|last53=Vasilyev|first53=S.|last54=Watkins|first54=S. L.|last55=Wilkerson|first55=J. F.|last56=Wiseman|first56=C.|last57=Xu|first57=W.|last58=Yu|first58=C.-H.|date=13 October 2023|title=Constraints on the Decay of <sup>180m</sup>Ta|arxiv=2306.01965|doi=10.1103/PhysRevLett.131.152501|volume=131|issue=15|pages=152501|journal=Phys. Rev. Lett.}}</ref><ref>{{Cite web|url=https://www.sciencenews.org/article/rarest-nucleus-reluctant-decay|title=Rarest nucleus reluctant to decay|last=Conover|first=Emily|date=2016-10-03|access-date=2016-10-05}}</ref><ref>{{Cite journal|last1=Lehnert|first1=Björn|last2=Hult|first2=Mikael|last3=Lutter|first3=Guillaume|last4=Zuber|first4=Kai|year=2017|title=Search for the decay of nature's rarest isotope <sup>180m</sup>Ta|arxiv=1609.03725|doi=10.1103/PhysRevC.95.044306|volume=95|issue=4|pages=044306|journal=Physical Review C|bibcode=2017PhRvC..95d4306L|s2cid=118497863 }}</ref> The very slow decay of {{SimpleNuclide|Ta|180|m}} 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.<ref>[https://web1.eng.famu.fsu.edu/~dommelen/quantum/style_a/ntgd.html Quantum mechanics for engineers] Leon van Dommelen, Florida State University</ref>

The very unusual nature of <sup>180m</sup>Ta is that the ground state of this isotope is less stable than the isomer. This phenomenon is exhibited in [[Physics:Bismuth-210m|bismuth-210m]] (<sup>210m</sup>Bi) and [[Physics:Americium-242m|americium-242m]] (<sup>242m</sup>Am), among other nuclides. {{SimpleNuclide|Ta|180}} has a half-life of only 8 hours. {{SimpleNuclide|Ta|180|m}} is the only naturally occurring [[Physics:Nuclear isomer|nuclear isomer]] (excluding radiogenic and cosmogenic short-living nuclides). It is also the rarest [[Chemistry:Primordial nuclide|primordial nuclide]] in the Universe observed for any element that has any stable isotopes.  In an [[Physics:S-process|s-process]] stellar environment with a thermal energy [[Physics:Boltzmann constant|k<sub>B</sub>]]T = 26 keV (i.e. a temperature of 300 million kelvin), the nuclear isomers are expected to be fully thermalized, meaning that <sup>180</sup>Ta rapidly transitions between spin states and its overall half-life is predicted to be 11 hours.<ref>{{cite journal|year=2007|title=Survival of Nature's Rarest Isotope 180Ta under Stellar Conditions|author=P. Mohr, F. Kaeppeler, and R. Gallino|journal=Phys. Rev. C|volume=75|pages=012802|doi=10.1103/PhysRevC.75.012802|arxiv=astro-ph/0612427|s2cid=44724195 }}</ref>

It is one of only [[Physics:Stable nuclide#Odd and even proton and neutron count|five stable nuclide]]s to have both an odd number of protons and an odd number of neutrons, the other four stable [[Physics:Even and odd atomic nuclei#Odd proton, odd neutron|odd-odd nuclides]] being [[Physics:Deuterium|<sup>2</sup>H]], [[Physics:Isotopes of lithium#Lithium-6|<sup>6</sup>Li]], [[Physics:Isotopes of boron|<sup>10</sup>B]] and [[Physics:Isotopes of nitrogen#Nitrogen-14|<sup>14</sup>N]].<ref>{{cite book|last=Various|editor=Lide, David R.|year=2002|title=Handbook of Chemistry & Physics|edition=88th|publisher=CRC|url=http://www.hbcpnetbase.com/|access-date=2008-05-23|isbn=978-0-8493-0486-6|oclc=179976746|archive-date=24 July 2017|archive-url=https://web.archive.org/web/20170724011402/http://www.hbcpnetbase.com/|url-status=dead}}</ref>

== References ==
<references />
* Isotope masses from:
**{{NUBASE 2003}}
* Isotopic compositions and standard atomic masses from:
**{{CIAAW 2005}}
* Half-life, spin, and isomer data selected from the following sources.
**{{NUBASE 2003}}
**{{NNDC}}
**{{CRC85|chapter=11}}

{{Navbox element isotopes}}

[[Category:Isotopes of tantalum| ]]
[[Category:Lists of isotopes by element|Tantalum]]

{{Sourceattribution|Isotopes of tantalum}}