Isotopes of barium

{{Short description|none}} {{Infobox barium isotopes}} Naturally occurring barium (₅₆Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001,<ref>{{cite journal |last1=Meshik |first1=A.P. |last2=Hohenberg |first2=C.M. |last3=Pravdivtseva |first3=O.V. |last4=Kapusta |first4=Y.S. |title=Weak decay of ¹³⁰Ba and ¹³²Ba: Geochemical measurements |date=2001 |journal=Physical Review C |volume=64 |issue=3 |pages=035205–1–035205–6 |doi=10.1103/PhysRevC.64.035205|url=https://zenodo.org/record/1063702 |bibcode=2001PhRvC..64c5205M }}</ref><ref>{{cite journal |author=M. Pujol |author2=B. Marty |author3=P. Burnard |author4=P. Philippot |year=2009|title=Xenon in Archean barite: Weak decay of ¹³⁰Ba, mass-dependent isotopic fractionation and implication for barite formation |journal=Geochimica et Cosmochimica Acta |volume=73|issue=22 |pages=6834–6846 |doi=10.1016/j.gca.2009.08.002|bibcode = 2009GeCoA..73.6834P }}</ref> presumably decaying by double electron capture with a half-life of (0.5–2.7)×10²¹ years (about 10¹¹ times the age of the universe). The two measurements are discordant; the above reflects the total range, the value in the table below is a crude average.

With the total range of mass numbers known 114 to 154, there are thirty-three known radioisotopes in addition to ¹³⁰Ba. The longest-lived of these is ¹³³Ba, which has a half-life of 10.538 years; all others have half-lives shorter than two weeks. The longest-lived isomers are ^133mBa at 38.90 hours and ^135m1Ba at 28.11 hours. The analogous ^137m1Ba (half-life 2.552 minutes) occurs in the decay of the common fission product caesium-137.

Barium-114 is theorized to undergo cluster decay, emitting a nucleus of stable ¹²C to produce ¹⁰²Sn. This decay has not been observed, with only an upper limit on the branching ratio of such decay (0.0034%).

== List of isotopes == {{Anchor|Barium-113}} <!--Please delete anchor(s) from the list above or table below if adding a dedicated isotope section(s).--> {{Isotopes table |symbol=Ba |refs=NUBASE2020, AME2020 II, IsotopeFRIB, IsomerFRIB |notes=m, unc(), mass#, spin(), spin#, daughter-st, daughter-nst, CD, EC, IT, n, p, discoveryname }} |-id=Barium-114 | rowspan=4|¹¹⁴Ba | rowspan=4 style="text-align:right" | 56 | rowspan=4 style="text-align:right" | 58 | rowspan=4|113.95072(11) | rowspan=4 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/114.pdf 1995] | rowspan=4|460(125)&nbsp;ms | β⁺ (79%) | ¹¹⁴Cs | rowspan=4|0+ | rowspan=4| | rowspan=4| |- | α (0.9%) | ¹¹⁰Xe |- | β⁺, p (20%) | ¹¹³Xe |- | CD (<.0034%) | ¹⁰²Sn, '''¹²C''' |-id=Barium-115 | rowspan=2|¹¹⁵Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 59 | rowspan=2|114.94748(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/115.pdf 1997] | rowspan=2|0.45(5)&nbsp;s | β⁺ | ¹¹⁵Cs | rowspan=2|5/2+# | rowspan=2| | rowspan=2| |- | β⁺, p (>15%) | ¹¹⁴Xe |-id=Barium-116 | rowspan=2|¹¹⁶Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 60 | rowspan=2|115.94162(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/116.pdf 1997] | rowspan=2|1.3(2)&nbsp;s | β⁺ (97%) | ¹¹⁶Cs | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺, p (3%) | ¹¹⁵Xe |-id=Barium-117 | rowspan=3|¹¹⁷Ba | rowspan=3 style="text-align:right" | 56 | rowspan=3 style="text-align:right" | 61 | rowspan=3|116.93832(27) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/117.pdf 1977] | rowspan=3|1.75(7)&nbsp;s | β⁺ (87%) | ¹¹⁷Cs | rowspan=3|(3/2+) | rowspan=3| | rowspan=3| |- | β⁺, p (13%) | ¹¹⁶Xe |- | β⁺, α (0.024%) | ¹¹³I |-id=Barium-118 | ¹¹⁸Ba | style="text-align:right" | 56 | style="text-align:right" | 62 | 117.93323(22)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/118.pdf 1997] | 5.2(2)&nbsp;s | β⁺ | ¹¹⁸Cs | 0+ | | |-id=Barium-119 | rowspan=2|¹¹⁹Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 63 | rowspan=2|118.93066(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/119.pdf 1974] | rowspan=2|5.4(3)&nbsp;s | β⁺ (75%) | ¹¹⁹Cs | rowspan=2|(3/2+)<ref name=zheng2021>{{cite journal |last1=Zheng |first1=K. K. |last2=Petrache |first2=C. M. |last3=Zhang |first3=Z. H. |last4=Astier |first4=A. |last5=Lv |first5=B. F. |last6=Greenlees |first6=P. T. |last7=Grahn |first7=T. |last8=Julin |first8=R. |last9=Juutinen |first9=S. |last10=Luoma |first10=M. |last11=Ojala |first11=J. |last12=Pakarinen |first12=J. |last13=Partanen |first13=J. |last14=Rahkila |first14=P. |last15=Ruotsalainen |first15=P. |last16=Sandzelius |first16=M. |last17=Sarén |first17=J. |last18=Tann |first18=H. |last19=Uusitalo |first19=J. |last20=Zimba |first20=G. |last21=Cederwall |first21=B. |last22=Aktas |first22=ö. |last23=Ertoprak |first23=A. |last24=Zhang |first24=W. |last25=Guo |first25=S. |last26=Liu |first26=M. L. |last27=Zhou |first27=X. H. |last28=Kuti |first28=I. |last29=Nyakó |first29=B. M. |last30=Sohler |first30=D. |last31=Timár |first31=J. |last32=Andreoiu |first32=C. |last33=Doncel |first33=M. |last34=Joss |first34=D. T. |last35=Page |first35=R. D. |title=Neutron excitations in Ba 119 |journal=Physical Review C |date=30 July 2021 |volume=104 |issue=1 |article-number=014326 |doi=10.1103/PhysRevC.104.014326 |url=https://jyx.jyu.fi/bitstream/123456789/77280/2/PhysRevC.104.014326.pdf}}</ref> | rowspan=2| | rowspan=2| |- | β⁺, p (25%) | ¹¹⁸Xe |-id=Barium-119m | style="text-indent:1em" | ^119mBa<ref name=zheng2021/> | colspan="3" style="text-indent:2em" | 66.0&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/119Ba-1.pdf 2021] | 360(20)&nbsp;ns | IT | ¹¹⁹Ba | (5/2−) | | |-id=Barium-120 | ¹²⁰Ba | style="text-align:right" | 56 | style="text-align:right" | 64 | 119.92604(32) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/120.pdf 1974] | 24(2)&nbsp;s | β⁺ | ¹²⁰Cs | 0+ | | |-id=Barium-121 | rowspan=2|¹²¹Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 65 | rowspan=2|120.92405(15) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/121.pdf 1975] | rowspan=2|29.7(15)&nbsp;s | β⁺ (99.98%) | ¹²¹Cs | rowspan=2|5/2+ | rowspan=2| | rowspan=2| |- | β⁺, p (0.02%) | ¹²⁰Xe |-id=Barium-122 | ¹²²Ba | style="text-align:right" | 56 | style="text-align:right" | 66 | 121.91990(3) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/122.pdf 1974] | 1.95(15)&nbsp;min | β⁺ | ¹²²Cs | 0+ | | |-id=Barium-123 | ¹²³Ba | style="text-align:right" | 56 | style="text-align:right" | 67 | 122.918781(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/123.pdf 1962] | 2.7(4)&nbsp;min | β⁺ | ¹²³Cs | 5/2+ | | |-id=Barium-123m | style="text-indent:1em" | ^123mBa | colspan="3" style="text-indent:2em" | 120.95(8)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/123Ba-1.pdf 1991] | 830(60)&nbsp;ns | IT | ¹²³Ba | 1/2+# | | |-id=Barium-124 | ¹²⁴Ba | style="text-align:right" | 56 | style="text-align:right" | 68 | 123.915094(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/124.pdf 1967] | 11.0(5)&nbsp;min | β⁺ | ¹²⁴Cs | 0+ | | |-id=Barium-125 | ¹²⁵Ba | style="text-align:right" | 56 | style="text-align:right" | 69 | 124.914472(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/125.pdf 1962] | 3.3(3)&nbsp;min | β⁺ | ¹²⁵Cs | 1/2+ | | |-id=Barium-125m | style="text-indent:1em" | ^125mBa | colspan="3" style="text-indent:2em" | 120(20)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/125Ba-1.pdf 2002] | 2.76(14)&nbsp;μs | IT | ¹²⁵Ba | (7/2−) | | |-id=Barium-126 | ¹²⁶Ba | style="text-align:right" | 56 | style="text-align:right" | 70 | 125.911250(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/126.pdf 1954] | 100(2)&nbsp;min | β⁺ | ¹²⁶Cs | 0+ | | |-id=Barium-127 | ¹²⁷Ba | style="text-align:right" | 56 | style="text-align:right" | 71 | 126.911091(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/127.pdf 1952] | 12.7(4)&nbsp;min | β⁺ | ¹²⁷Cs | 1/2+ | | |-id=Barium-127m | style="text-indent:1em" | ^127mBa | colspan="3" style="text-indent:2em" | 80.32(11)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/127Ba-1.pdf 1992] | 1.93(7)&nbsp;s | IT | ¹²⁷Ba | 7/2− | | |-id=Barium-128 | ¹²⁸Ba | style="text-align:right" | 56 | style="text-align:right" | 72 | 127.9083524(17) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/128.pdf 1950] | 2.43(5)&nbsp;d | EC | ¹²⁸Cs | 0+ | | |-id=Barium-129 | ¹²⁹Ba | style="text-align:right" | 56 | style="text-align:right" | 73 | 128.908683(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/129.pdf 1950] | 2.23(11)&nbsp;h | β⁺ | ¹²⁹Cs | 1/2+ | | |-id=Barium-129m | rowspan=2 style="text-indent:1em" | ^129mBa | rowspan=2 colspan="3" style="text-indent:2em" | 8.42(6)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/129Ba-1.pdf 1961] | rowspan=2|2.135(10)&nbsp;h | β⁺ | ¹²⁹Cs | rowspan=2|7/2+ | rowspan=2| | rowspan=2| |- | IT? | ¹²⁹Ba |-id=Barium-130 | ¹³⁰Ba<ref group="n">Primordial radionuclide</ref> | style="text-align:right" | 56 | style="text-align:right" | 74 | 129.9063260(3) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/130.pdf 1936] | '''≈&nbsp;1×10²¹&nbsp;y''' | εε | '''¹³⁰Xe''' | 0+ | 0.0011(1) | |-id=Barium-130m | style="text-indent:1em" | ^130mBa | colspan="3" style="text-indent:2em" | 2475.12(18)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/130Ba-1.pdf 1966] | 9.54(14)&nbsp;ms | IT | '''''¹³⁰Ba''''' | 8− | | |-id=Barium-131 | ¹³¹Ba | style="text-align:right" | 56 | style="text-align:right" | 75 | 130.9069463(4) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/131.pdf 1947] | 11.52(1)&nbsp;d | β⁺ | ¹³¹Cs | 1/2+ | | |-id=Barium-131m | style="text-indent:1em" | ^131mBa | colspan="3" style="text-indent:2em" | 187.995(9)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/131Ba-1.pdf 1963] | 14.26(9)&nbsp;min | IT | ¹³¹Ba | 9/2− | | |-id=Barium-132 | ¹³²Ba | style="text-align:right" | 56 | style="text-align:right" | 76 | 131.9050612(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/132.pdf 1936] | colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo β⁺β⁺ decay to '''¹³²Xe''' with a half-life over 3×10²⁰ years</ref> | 0+ | 0.0010(1) | |-id=Barium-133 | ¹³³Ba | style="text-align:right" | 56 | style="text-align:right" | 77 |132.9060074(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/133.pdf 1941] | 10.5379(16)&nbsp;y | EC | '''¹³³Cs''' | 1/2+ | | |-id=Barium-133m | rowspan=2 style="text-indent:1em" | ^133mBa | rowspan=2 colspan="3" style="text-indent:2em" | 288.252(9)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/133Ba-1.pdf 1941] | rowspan=2|38.90(6)&nbsp;h | IT (99.99%) | ¹³³Ba | rowspan=2|11/2− | rowspan=2| | rowspan=2| |- | EC (0.0104%) | '''¹³³Cs''' |-id=Barium-134 | ¹³⁴Ba<ref group="n" name="FP">Fission product</ref> | style="text-align:right" | 56 | style="text-align:right" | 78 | 133.90450825(27) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/134.pdf 1936] | colspan=3 align=center|'''Stable''' | 0+ | 0.0242(15) | |-id=Barium-134m | style="text-indent:1em" | ^134mBa | colspan="3" style="text-indent:2em" | 2957.2(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/134Ba-1.pdf 1980] | 2.61(13)&nbsp;μs | IT | '''¹³⁴Ba''' | 10+ | | |-id=Barium-135 | ¹³⁵Ba | style="text-align:right" | 56 | style="text-align:right" | 79 | 134.90568845(26) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/135.pdf 1931] | colspan=3 align=center|'''Stable''' | 3/2+ | 0.0659(10) | |-id=Barium-135m1 | style="text-indent:1em" | ^135m1Ba | colspan="3" style="text-indent:2em" | 268.218(20)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/135Ba-1.pdf 1948] | 28.11(2)&nbsp;h | IT | '''¹³⁵Ba''' | 11/2− | | |-id=Barium-135m2 | style="text-indent:1em" | ^135m2Ba | colspan="3" style="text-indent:2em" | 2388.0(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/135Ba-2.pdf 2018] | 1.06(4)&nbsp;ms | IT | '''¹³⁵Ba''' | (23/2+) | | |-id=Barium-136 | ¹³⁶Ba | style="text-align:right" | 56 | style="text-align:right" | 80 |135.90457580(26) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/136.pdf 1931] | colspan=3 align=center|'''Stable''' | 0+ | 0.0785(24) | |-id=Barium-136m1 | style="text-indent:1em" | ^136m1Ba | colspan="3" style="text-indent:2em" | 2030.535(18)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/136Ba-1.pdf 1965] | 308.4(19)&nbsp;ms | IT | '''¹³⁶Ba''' | 7− | | |-id=Barium-136m2 | style="text-indent:1em" | ^136m2Ba | colspan="3" style="text-indent:2em" | 3357.19(25)&nbsp;keV | style="text-align:center" | (2004)<ref group="n">Half-life shorter than 100 ns, not included in the discovery database.</ref> | 91(2)&nbsp;ns | IT | '''¹³⁶Ba''' | 10+ | | |-id=Barium-137 | ¹³⁷Ba<ref group="n" name="FP" /> | style="text-align:right" | 56 | style="text-align:right" | 81 |136.90582721(27) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/137.pdf 1931] | colspan=3 align=center|'''Stable''' | 3/2+ | 0.1123(23) | |-id=Barium-137m1 | style="text-indent:1em" | ^137m1Ba<ref group="n" name="FP" /> | colspan="3" style="text-indent:2em" | 661.659(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/137Ba-1.pdf 1948] | 2.552(1)&nbsp;min | IT | '''¹³⁷Ba''' | 11/2− | | |-id=Barium-137m2 | style="text-indent:1em" | ^137m2Ba | colspan="3" style="text-indent:2em" | 2349.1(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/137Ba-2.pdf 1973] | 589(20)&nbsp;ns | IT | '''¹³⁷Ba''' | (19/2−) | | |-id=Barium-138 | ¹³⁸Ba<ref group="n" name="FP" /> | style="text-align:right" | 56 | style="text-align:right" | 82 | 137.90524706(27) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/138.pdf 1924] | colspan=3 align=center|'''Stable''' | 0+ | 0.7170(29) | |-id=Barium-138m | style="text-indent:1em" | ^138mBa | colspan="3" style="text-indent:2em" | 2090.536(21)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/56/138Ba-1.pdf 1971] | 850(100)&nbsp;ns | IT | '''¹³⁸Ba''' | 6+ | | |-id=Barium-139 | ¹³⁹Ba<ref group="n" name="FP" /> | style="text-align:right" | 56 | style="text-align:right" | 83 | 138.90884116(27) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/139.pdf 1937] | 82.93(9)&nbsp;min | β⁻ | '''¹³⁹La''' | 7/2− | | |-id=Barium-140 | ¹⁴⁰Ba<ref group="n" name="FP" /> | style="text-align:right" | 56 | style="text-align:right" | 84 | 139.910608(8) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/140.pdf 1939] | 12.7534(21)&nbsp;d | β⁻ | ¹⁴⁰La | 0+ | | |-id=Barium-141 | ¹⁴¹Ba | style="text-align:right" | 56 | style="text-align:right" | 85 | 140.914404(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/141.pdf 1951] | 18.27(7)&nbsp;min | β⁻ | ¹⁴¹La | 3/2− | | |-id=Barium-142 | ¹⁴²Ba | style="text-align:right" | 56 | style="text-align:right" | 86 | 141.916433(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/142.pdf 1959] | 10.6(2)&nbsp;min | β⁻ | ¹⁴²La | 0+ | | |-id=Barium-143 | ¹⁴³Ba | style="text-align:right" | 56 | style="text-align:right" | 87 | 142.920625(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/143.pdf 1962] | 14.5(3)&nbsp;s | β⁻ | ¹⁴³La | 5/2− | | |-id=Barium-144 | ¹⁴⁴Ba | style="text-align:right" | 56 | style="text-align:right" | 88 |143.922955(8) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/144.pdf 1967] | 11.73(8)&nbsp;s | β⁻ | ¹⁴⁴La | 0+ | | |-id=Barium-145 | ¹⁴⁵Ba | style="text-align:right" | 56 | style="text-align:right" | 89 | 144.927518(9) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/145.pdf 1974] | 4.31(16)&nbsp;s | β⁻ | ¹⁴⁵La | 5/2− | | |-id=Barium-146 | ¹⁴⁶Ba | style="text-align:right" | 56 | style="text-align:right" | 90 | 145.9303632(19) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/146.pdf 1970] | 2.15(4)&nbsp;s | β⁻ | ¹⁴⁶La | 0+ | | |-id=Barium-147 | rowspan=2|¹⁴⁷Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 91 | rowspan=2|146.935304(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/147.pdf 1978] | rowspan=2|893(1)&nbsp;ms | β⁻ (99.93%) | ¹⁴⁷La | rowspan=2|5/2− | rowspan=2| | rowspan=2| |- | β⁻, n (0.07%) | ¹⁴⁶La |-id=Barium-148 | rowspan=2|¹⁴⁸Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 92 | rowspan=2| 147.9382230(16) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/148.pdf 1979] | rowspan=2|620(5)&nbsp;ms | β⁻ (99.6%) | ¹⁴⁸La | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (0.4%) | ¹⁴⁷La |-id=Barium-149 | rowspan=2|¹⁴⁹Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 93 | rowspan=2|148.9432840(27) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/149.pdf 1993] | rowspan=2|349(4)&nbsp;ms | β⁻ (96.1%) | ¹⁴⁹La | rowspan=2|3/2−# | rowspan=2| | rowspan=2| |- | β⁻, n (3.9%) | ¹⁴⁸La |-id=Barium-150 | rowspan=2|¹⁵⁰Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 94 | rowspan=2| 149.946441(6) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/150.pdf 1994] | rowspan=2|258(5)&nbsp;ms | β⁻ (99.0%) | ¹⁵⁰La | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (1.0%) | ¹⁴⁹La |-id=Barium-151 | rowspan=2|¹⁵¹Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 95 | rowspan=2|150.95176(43)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/151.pdf 1994] | rowspan=2|167(5)&nbsp;ms | β⁻ | ¹⁵¹La | rowspan=2|3/2−# | rowspan=2| | rowspan=2| |- | β⁻, n? | ¹⁵⁰La |-id=Barium-152 | rowspan=2|¹⁵²Ba | rowspan=2 style="text-align:right" | 56 | rowspan=2 style="text-align:right" | 96 | rowspan=2|151.95533(43)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/152.pdf 2010] | rowspan=2|139(8)&nbsp;ms | β⁻ | ¹⁵²La | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n? | ¹⁵¹La |-id=Barium-153 | rowspan=3|¹⁵³Ba | rowspan=3 style="text-align:right" | 56 | rowspan=3 style="text-align:right" | 97 | rowspan=3|152.96085(43)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/153.pdf 2017] | rowspan=3|113(39)&nbsp;ms | β⁻ | ¹⁵³La | rowspan=3|5/2−# | rowspan=3| | rowspan=3| |- | β⁻, n? | ¹⁵²La |- | β⁻, 2n? | ¹⁵¹La |-id=Barium-154 | ¹⁵⁴Ba | style="text-align:right" | 56 | style="text-align:right" | 98 |153.96466(54)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/154.pdf 2017] | 53(48)&nbsp;ms | β⁻ | ¹⁵⁴La | 0+ | | |-id=Barium-155 | ¹⁵⁵Ba<ref name=sumikama2026>{{cite journal |last1=Sumikama |first1=Toshiyuki |last2=Fukuda |first2=Naoki |last3=Kubo |first3=Toshiyuki |last4=Suzuki |first4=Hiroshi |last5=Takeda |first5=Hiroyuki |last6=Inabe |first6=Naohito |last7=Kameda |first7=Daisuke |last8=Ahn |first8=Deuk Soon |last9=Murai |first9=Daichi |last10=Yoshida |first10=Koichi |last11=Kusaka |first11=Kensuke |last12=Yanagisawa |first12=Yoshiyuki |last13=Ohtake |first13=Masao |last14=Shimizu |first14=Yohei |last15=Sato |first15=Yuki |last16=Sato |first16=Hiromi |last17=Otsu |first17=Hideaki |last18=Baba |first18=Hidetada |last19=Lorusso |first19=Giuseppe |last20=Söderström |first20=Pär-Anders |last21=Isobe |first21=Tadaaki |last22=Imai |first22=Nobuaki |last23=Mukai |first23=Momo |last24=Kimura |first24=Sota |last25=Miyatake |first25=Hiroari |last26=Iwasa |first26=Naohito |last27=Yagi |first27=Ayumi |last28=Yokoyama |first28=Rin |last29=Tarasov |first29=Oleg Borisovich |last30=Geissel |first30=Hans |title=Expanding the Isotopic Frontier: Seven New Neutron-Rich Rare-Earth Isotopes Observed at RIKEN RI Beam Factory |journal=Journal of the Physical Society of Japan |date=15 February 2026 |volume=95 |issue=2 |doi=10.7566/JPSJ.95.024202}}</ref> | style="text-align:right" | 56 | style="text-align:right" | 99 | | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/56/155.pdf 2026] | | | | | | {{Isotopes table/footer}}

== Barium-131 == Barium-131 is a radioactive isotope of barium with a half-life of 11.52 days. It decays to caesium-131 by electron capture.{{NUBASE2020|ref}} It is produced by irradiation of caesium with protons with the reaction ¹³³Cs(p,3n)¹³¹Ba. It is developed for SPECT imaging and can be combined with the alpha-emitter radium-223.<ref>{{cite journal | last1=Reissig | first1=Falco | last2=Bauer | first2=David | last3=Ullrich | first3=Martin | last4=Kreller | first4=Martin | last5=Pietzsch | first5=Jens | last6=Mamat | first6=Constantin | last7=Kopka | first7=Klaus | last8=Pietzsch | first8=Hans-Jürgen | last9=Walther | first9=Martin | title=Recent Insights in Barium-131 as a Diagnostic Match for Radium-223: Cyclotron Production, Separation, Radiolabeling, and Imaging | journal=Pharmaceuticals (Basel, Switzerland) | volume=13 | issue=10 | date=2020-09-25 | issn=1424-8247 | pmid=32992909 | pmc=7599757 | doi=10.3390/ph13100272 | doi-access=free | page=272}}</ref>

== See also == '''Daughter products other than barium''' * Isotopes of lanthanum * Isotopes of caesium * Isotopes of xenon * Isotopes of iodine * Isotopes of tin * Isotopes of carbon

== References == {{Reflist}}

{{Navbox element isotopes}} {{Authority control}}

Category:Isotopes of barium Category:Barium Barium