Isotopes of lanthanum

{{Short description|Isotopes}} {{Infobox lanthanum isotopes}} thumb|Stable Z/N chart of La and Ba Naturally occurring lanthanum (₅₇La) is composed of one stable (¹³⁹La) and one radioactive (¹³⁸La) isotope, with the stable isotope, ¹³⁹La, being the most abundant (99.911% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being ¹³⁸La, with a half-life of 1.03×10¹¹ years; ¹³⁷La, with a half-life of 60,000 years and ¹⁴⁰La, with a half-life of 40.289 hours. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these less than a minute. This element also has 12 nuclear isomers, the longest-lived of which is ^132mLa, with a half-life of 24.3 minutes. Lighter isotopes mostly decay to isotopes of barium and heavy ones mostly decay to isotopes of cerium. ¹³⁸La can decay to both.

The known isotopes of lanthanum range from ¹¹⁶La to ¹⁵⁵La.

== List of isotopes == {{Anchor}} <!--Please delete anchor(s) from the list above or table below if adding a dedicated isotope section(s).--> {{Isotopes table |symbol=La |refs=NUBASE2020, AME2020 II, <!-- updated 2024-12-28 --> IsotopeFRIB, IsomerFRIB |notes=m, unc(), mass#, exen#, spin(), spin#, hl#, hl-nst, daughter-st, daughter-nst, p, n, IT, EC, discoveryname }} |-id=Lanthanum-116 | rowspan=2|¹¹⁶La<ref name=zhang2022>{{cite journal |last1=Zhang |first1=Wei |last2=Cederwall |first2=Bo |last3=Aktas |first3=Özge |last4=Liu |first4=Xiaoyu |last5=Ertoprak |first5=Aysegül |last6=Nyberg |first6=Ayse |last7=Auranen |first7=Kalle |last8=Alayed |first8=Betool |last9=Badran |first9=Hussam |last10=Boston |first10=Helen |last11=Doncel |first11=Maria |last12=Forsberg |first12=Ulrika |last13=Grahn |first13=Tuomas |last14=Greenlees |first14=Paul T. |last15=Guo |first15=Song |last16=Heery |first16=Jacob |last17=Hilton |first17=Joshua |last18=Jenkins |first18=David |last19=Julin |first19=Rauno |last20=Juutinen |first20=Sakari |last21=Luoma |first21=Minna |last22=Neuvonen |first22=Olavi |last23=Ojala |first23=Joonas |last24=Page |first24=Robert D. |last25=Pakarinen |first25=Janne |last26=Partanen |first26=Jari |last27=Paul |first27=Edward S. |last28=Petrache |first28=Costel |last29=Rahkila |first29=Panu |last30=Ruotsalainen |first30=Panu |last31=Sandzelius |first31=Mikael |last32=Sarén |first32=Jan |last33=Szwec |first33=Stuart |last34=Tann |first34=Holly |last35=Uusitalo |first35=Juha |last36=Wadsworth |first36=Robert |title=Observation of the proton emitter {{ComplexNuclide|La|116|q=59}} |journal=Communications Physics |date=14 November 2022 |volume=5 |issue=1 |pages=1–8 |doi=10.1038/s42005-022-01069-w |s2cid=253512231 |issn=2399-3650|doi-access=free |url=https://jyx.jyu.fi/bitstream/123456789/84039/1/s42005-022-01069-w.pdf }}</ref> | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 59 | rowspan=2|115.95701(35)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/116.pdf 2022] | rowspan=2|50(22)&nbsp;ms | p (~60%) | ¹¹⁵Ba | rowspan=2| | rowspan=2| | rowspan=2| |- | β⁺ (~40%) | ¹¹⁶Ba |-id=Lanthanum-116m | style="text-indent:1em" | ^116mLa<ref name=zhang2022/> | colspan="3" style="text-indent:2em" | 182&nbsp;keV | style="text-align:center" |[https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/116La-1.pdf 2022] | {{val|2.0|2.8|0.8|u=μs}} | IT | ¹¹⁶La | | | |-id=Lanthanum-117 | rowspan=2|¹¹⁷La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 60 | rowspan=2|116.95033(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/117.pdf 2001] | rowspan=2|21.6(31)&nbsp;ms | p (94%) | ¹¹⁶Ba | rowspan=2|(3/2+) | rowspan=2| | rowspan=2| |- | β⁺ (6%) | ¹¹⁷Ba |-id=Lanthanum-117m | style="text-indent:1em" | ^117mLa<ref name=zhang2022/> | colspan="3" style="text-indent:2em" | 192&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/117La-1.pdf 2022] | {{val|2.7|1.3|0.7|u=μs}} | IT | ¹¹⁷La | (7/2−) | | |-id=Lanthanum-118 | ¹¹⁸La<ref name="suzuki2025">{{cite journal |last1=Suzuki |first1=H |last2=Fukuda |first2=N |last3=Takeda |first3=H |last4=Shimizu |first4=Y |last5=Yoshimoto |first5=M |last6=Togano |first6=Y |last7=Sato |first7=H |last8=Kitamura |first8=N |last9=Hanai |first9=S |last10=Momota |first10=S |last11=Kusaka |first11=K |last12=Yanagisawa |first12=Y |last13=Ohtake |first13=M |last14=Sumikama |first14=T |last15=Fukunishi |first15=N |last16=Michimasa |first16=S |title=Discovery of Proton-Rich Radioactive Isotopes in the Z = 60 Region Produced by the Projectile Fragmentation of a 345-MeV/Nucleon 238U Beam |journal=Progress of Theoretical and Experimental Physics |date=7 November 2025 |volume=2025 |issue=11 |doi=10.1093/ptep/ptaf149|doi-access=free }}</ref> | style="text-align:right" | 57 | style="text-align:right" | 61 | 117.94673(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/118.pdf 2025] | 200#&nbsp;ms [>310&nbsp;ns] | | | 1−# | | |-id=Lanthanum-119 | ¹¹⁹La<ref name="suzuki2025"/> | style="text-align:right" | 57 | style="text-align:right" | 62 | 118.94093(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/119.pdf 2025] | 1#&nbsp;s [>310&nbsp;ns] | | | 11/2−# | | |-id=Lanthanum-120 | rowspan=2|¹²⁰La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 63 | rowspan=2|119.93820(32)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/120.pdf 1984] | rowspan=2|2.8(2)&nbsp;s | β⁺ | ¹²⁰Ba | rowspan=2|4+<ref name=jodidar2024>{{cite journal |last1=Jodidar |first1=P.M. |last2=Petrache |first2=C.M. |last3=Lv |first3=B.F. |last4=Lawrie |first4=E.A. |last5=Astier |first5=A. |last6=Guo |first6=S. |last7=Zheng |first7=K.K. |last8=Auranen |first8=K. |last9=Briscoe |first9=A.D. |last10=Grahn |first10=T. |last11=Greenlees |first11=P.T. |last12=Illana |first12=A. |last13=Joukainen |first13=H. |last14=Julin |first14=R. |last15=Louko |first15=J. |last16=Luoma |first16=M. |last17=Jutila |first17=H. |last18=Ojala |first18=J. |last19=Pakarinen |first19=J. |last20=Plaza |first20=A.M. |last21=Rahkila |first21=P. |last22=Ruotsalainen |first22=P. |last23=Sarén |first23=J. |last24=Tolosa-Delgado |first24=A. |last25=Uusitalo |first25=J. |last26=Zimba |first26=G. |last27=Kuti |first27=I. |last28=Krakó |first28=A. |last29=Andreoiu |first29=C. |last30=Joss |first30=D.T. |last31=Page |first31=R.D. |last32=Cederlöf |first32=E.A. |last33=Ertoprak |first33=A. |title=First observation of excited states in 120La and its impact on the shape evolution in the A ≈ 120 mass region |journal=Physics Letters B |date=August 2024 |volume=855 |article-number=138806 |doi=10.1016/j.physletb.2024.138806|url=https://jyx.jyu.fi/bitstream/123456789/96806/1/1-s2.0-S0370269324003642-main.pdf }}</ref> | rowspan=2| | rowspan=2| |- | β⁺, p (?%) | ¹¹⁹Cs |-id=Lanthanum-121 | ¹²¹La | style="text-align:right" | 57 | style="text-align:right" | 64 | 120.93324(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/121.pdf 1988] | 5.3(2)&nbsp;s | β⁺ | ¹²¹Ba | 11/2−# | | |-id=Lanthanum-122 | rowspan=2|¹²²La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 65 | rowspan=2|121.93071(32)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/122.pdf 1984] | rowspan=2|8.6(5)&nbsp;s | β⁺ | ¹²²Ba | rowspan=2|2+<ref name=jodidar2024/> | rowspan=2| | rowspan=2| |- | β⁺, p (?%) | ¹²¹Cs |-id=Lanthanum-123 | ¹²³La | style="text-align:right" | 57 | style="text-align:right" | 66 | 122.92630(21)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/123.pdf 1978] | 17(3)&nbsp;s | β⁺ | ¹²³Ba | 11/2−# | | |-id=Lanthanum-124 | ¹²⁴La | style="text-align:right" | 57 | style="text-align:right" | 67 | 123.924574(61) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/124.pdf 1978] | 29.21(17)&nbsp;s | β⁺ | ¹²⁴Ba | (7−, 8−) | | |-id=Lanthanum-124m | style="text-indent:1em" | ^124mLa<ref group="n" name="order">Order of ground state and isomer is uncertain.</ref> | colspan="3" style="text-indent:2em" | 100(100)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/124La-1.pdf 1997] | 21(4)&nbsp;s | β⁺ | ¹²⁴Ba | 2−# | | |-id=Lanthanum-125 | ¹²⁵La | style="text-align:right" | 57 | style="text-align:right" | 68 | 124.920816(28) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/125.pdf 1973] | 64.8(12)&nbsp;s | β⁺ | ¹²⁵Ba | 11/2−# | | |-id=Lanthanum-125m | style="text-indent:1em" | ^125mLa | colspan="3" style="text-indent:2em" | 107.00(10)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/125La-1.pdf 1999] | 390(40)&nbsp;ms | IT | ¹²⁵La | (3/2+) | | |-id=Lanthanum-126 | ¹²⁶La | style="text-align:right" | 57 | style="text-align:right" | 69 | 125.919513(97) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/126.pdf 1961] | 54(2)&nbsp;s | β⁺ | ¹²⁶Ba | 5−# | | |-id=Lanthanum-126m | style="text-indent:1em" | ^126mLa<ref group="n" name="order"/> | colspan="3" style="text-indent:2em" | 210(410)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/126La-1.pdf 1998] | 20(20)&nbsp;s | β⁺ | ¹²⁶Ba | 1−# | | |-id=Lanthanum-127 | ¹²⁷La | style="text-align:right" | 57 | style="text-align:right" | 70 | 126.916375(28) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/127.pdf 1963] | 5.1(1)&nbsp;min | β⁺ | ¹²⁷Ba | (11/2−) | | |-id=Lanthanum-127m | style="text-indent:1em" | ^127mLa | colspan="3" style="text-indent:2em" | 14.2(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/127La-1.pdf 1973] | 3.7(4)&nbsp;min | β⁺ | ¹²⁷Ba | (3/2+) | | |-id=Lanthanum-128 | ¹²⁸La | style="text-align:right" | 57 | style="text-align:right" | 71 | 127.915592(58) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/128.pdf 1961] | 5.18(14)&nbsp;min | β⁺ | ¹²⁸Ba | (5+) | | |-id=Lanthanum-128m | style="text-indent:1em" | ^128mLa<ref group="n" name="order"/> | colspan="3" style="text-indent:2em" | 100(100)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/128La-1.pdf 1997] | <&nbsp;1.4&nbsp;min | β⁺ | ¹²⁸Ba | (1+, 2−) | | |-id=Lanthanum-129 | ¹²⁹La | style="text-align:right" | 57 | style="text-align:right" | 72 | 128.912696(23) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/129.pdf 1963] | 11.6(2)&nbsp;min | β⁺ | ¹²⁹Ba | (3/2+) | | |-id=Lanthanum-129m | style="text-indent:1em" | ^129mLa | colspan="3" style="text-indent:2em" | 172.33(20)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/129La-1.pdf 1969] | 560(50)&nbsp;ms | IT | ¹²⁹La | (11/2−) | | |-id=Lanthanum-130 | ¹³⁰La | style="text-align:right" | 57 | style="text-align:right" | 73 | 129.912369(28) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/130.pdf 1961] | 8.7(1)&nbsp;min | β⁺ | '''''¹³⁰Ba''''' | 3(+) | | |-id=Lanthanum-130m | style="text-indent:1em" | ^130mLa | colspan="3" style="text-indent:2em" | 214.0(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/130La-1.pdf 2012] | 742(28)&nbsp;ns | IT | ¹³⁰La | (5+) | | |-id=Lanthanum-131 | ¹³¹La | style="text-align:right" | 57 | style="text-align:right" | 74 | 130.910070(30) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/131.pdf 1951] | 59(2)&nbsp;min | β⁺ | ¹³¹Ba | 3/2+ | | |-id=Lanthanum-131m | style="text-indent:1em" | ^131mLa | colspan="3" style="text-indent:2em" | 304.52(24)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/131La-1.pdf 1966] | 170(10)&nbsp;μs | IT | ¹³¹La | 11/2− | | |-id=Lanthanum-132 | ¹³²La | style="text-align:right" | 57 | style="text-align:right" | 75 | 131.910119(39) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/132.pdf 1951] | 4.59(4)&nbsp;h | β⁺ | '''¹³²Ba''' | 2− | | |-id=Lanthanum-132m | rowspan=2 style="text-indent:1em" | ^132mLa | rowspan=2 colspan="3" style="text-indent:2em" | 188.20(11)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/132La-1.pdf 1969] | rowspan=2|24.3(5)&nbsp;min | IT (76%) | ¹³²La | rowspan=2|6− | rowspan=2| | rowspan=2| |- | β⁺ (24%) | '''¹³²Ba''' |-id=Lanthanum-133 | ¹³³La | style="text-align:right" | 57 | style="text-align:right" | 76 | 132.908218(30) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/133.pdf 1950] | 3.912(8)&nbsp;h | β⁺ | ¹³³Ba | 5/2+ | | |-id=Lanthanum-134 | ¹³⁴La | style="text-align:right" | 57 | style="text-align:right" | 77 | 133.908514(21) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/134.pdf 1951] | 6.45(16)&nbsp;min | β⁺ | '''¹³⁴Ba''' | 1+ | | |-id=Lanthanum-134m | style="text-indent:1em" | ^134mLa | colspan="3" style="text-indent:2em" | 440(100)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/134La-1.pdf 1985] | 29(4)&nbsp;μs | IT | ¹³⁴La | (6−) | | |-id=Lanthanum-135 | ¹³⁵La | style="text-align:right" | 57 | style="text-align:right" | 78 | 134.906984(10) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/135.pdf 1948] | 18.91(2)&nbsp;h | β⁺ | '''¹³⁵Ba''' | 5/2+ | | |-id=Lanthanum-136 | ¹³⁶La | style="text-align:right" | 57 | style="text-align:right" | 79 | 135.907635(57) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/136.pdf 1950] | 9.87(3)&nbsp;min | β⁺ | '''¹³⁶Ba''' | 1+ | | |-id=Lanthanum-136m1 | style="text-indent:1em" | ^136m1La | colspan="3" style="text-indent:2em" | 259.5(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/136La-1.pdf 1966] | 114(5)&nbsp;ms | IT | ¹³⁶La | (7−) | | |-id=Lanthanum-136m2 | style="text-indent:1em" | ^136m2La | colspan="3" style="text-indent:2em" | 2520.6(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/136La-2.pdf 2015] | 187(27)&nbsp;ns | IT | ¹³⁶La | (14+) | | |-id=Lanthanum-137 | ¹³⁷La | style="text-align:right" | 57 | style="text-align:right" | 80 | 136.9064504(18) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/137.pdf 1948] | 6(2)×10⁴&nbsp;y | EC | '''¹³⁷Ba''' | 7/2+ | | |-id=Lanthanum-137m | style="text-indent:1em" | ^137mLa | colspan="3" style="text-indent:2em" | 1869.50(21)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/137La-1.pdf 1982] | 342(25)&nbsp;ns | IT | ¹³⁷La | 19/2− | | |-id=Lanthanum-138 | rowspan=2|¹³⁸La<ref group="n">Primordial radionuclide</ref> | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 81 | rowspan=2|137.90712404(45) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/138.pdf 1947] | rowspan=2|'''1.03(1)×10¹¹&nbsp;y''' | β⁺ (65.5%) | '''¹³⁸Ba''' | rowspan=2|5+ | rowspan=2|8.881(71)×10⁻⁴ | rowspan=2| |- | β⁻ (34.5%) | '''¹³⁸Ce''' |-id=Lanthanum-138m1 | style="text-indent:1em" | ^138m1La | colspan="3" style="text-indent:2em" | 72.57(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/138La-1.pdf 1975] | 116(5)&nbsp;ns | IT | '''''¹³⁸La''''' | (3)+ | | |-id=Lanthanum-138m2 | style="text-indent:1em" | ^138m2La | colspan="3" style="text-indent:2em" | 738.80(20)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/138La-2.pdf 2014] | 2.0(3)&nbsp;μs | IT | '''''¹³⁸La''''' | 7− | | |-id=Lanthanum-139 | ¹³⁹La<ref group="n" name="FP">Fission product</ref> | style="text-align:right" | 57 | style="text-align:right" | 82 | 138.90636293(65) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/139.pdf 1924] | colspan=3 align=center|'''Stable''' | 7/2+ | 0.9991119(71) | |-id=Lanthanum-139m | style="text-indent:1em" | ^139mLa | colspan="3" style="text-indent:2em" | 1800.4(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/139La-1.pdf 2012] | 315(35)&nbsp;ns | IT | '''¹³⁹La''' | (17/2+) | | |-id=Lanthanum-140 | ¹⁴⁰La<ref group="n" name="FP" /> | style="text-align:right" | 57 | style="text-align:right" | 83 | 139.90948729(65) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/140.pdf 1935] | 40.289(4)&nbsp;h | β⁻ | '''¹⁴⁰Ce''' | 3− | | |-id=Lanthanum-141 | ¹⁴¹La | style="text-align:right" | 57 | style="text-align:right" | 84 | 140.9109712(44) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/141.pdf 1951] | 3.92(3)&nbsp;h | β⁻ | ¹⁴¹Ce | (7/2+) | | |-id=Lanthanum-142 | ¹⁴²La | style="text-align:right" | 57 | style="text-align:right" | 85 | 141.9140908(67) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/142.pdf 1953] | 91.1(5)&nbsp;min | β⁻ | '''¹⁴²Ce''' | 2− | | |-id=Lanthanum-142m | style="text-indent:1em" | ^142mLa | colspan="3" style="text-indent:2em" | 145.82(8)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/142La-1.pdf 1983] | 0.87(17)&nbsp;μs | IT | ¹⁴²La | (4)− | | |-id=Lanthanum-143 | ¹⁴³La | style="text-align:right" | 57 | style="text-align:right" | 86 | 142.9160795(79) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/143.pdf 1951] | 14.2(1)&nbsp;min | β⁻ | ¹⁴³Ce | (7/2)+ | | |-id=Lanthanum-144 | ¹⁴⁴La | style="text-align:right" | 57 | style="text-align:right" | 87 | 143.919646(14) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/144.pdf 1967] | 44.0(7)&nbsp;s | β⁻ | ¹⁴⁴Ce | (3−) | | |-id=Lanthanum-145 | ¹⁴⁵La | style="text-align:right" | 57 | style="text-align:right" | 88 | 144.921808(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/145.pdf 1974] | 24.8(20)&nbsp;s | β⁻ | ¹⁴⁵Ce | (5/2+) | | |-id=Lanthanum-146 | ¹⁴⁶La | style="text-align:right" | 57 | style="text-align:right" | 89 | 145.9256880(18) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/146.pdf 1974] | 9.9(1)&nbsp;s | β⁻ | ¹⁴⁶Ce | (5−) | | |-id=Lanthanum-146m | style="text-indent:1em" | ^146mLa | colspan="3" style="text-indent:2em" | 141.5(24)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/57/146La-1.pdf 1979] | 6.08(22)&nbsp;s | β⁻ | ¹⁴⁶Ce | (1−, 2−) | | |-id=Lanthanum-147 | rowspan=2|¹⁴⁷La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 90 | rowspan=2|146.928418(12) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/147.pdf 1979] | rowspan=2|4.026(20)&nbsp;s | β⁻ (99.96%) | ¹⁴⁷Ce | rowspan=2|(5/2+) | rowspan=2| | rowspan=2| |- | β⁻, n (0.041%) | ¹⁴⁶Ce |-id=Lanthanum-148 | rowspan=2|¹⁴⁸La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 91 | rowspan=2|147.932679(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/148.pdf 1982] | rowspan=2|1.414(25)&nbsp;s | β⁻ (99.82%) | ¹⁴⁸Ce | rowspan=2|(2−) | rowspan=2| | rowspan=2| |- | β⁻, n (0.18%) | ¹⁴⁷Ce |-id=Lanthanum-149 | rowspan=2|¹⁴⁹La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 92 | rowspan=2|148.93535(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/149.pdf 1979] | rowspan=2|1.071(22)&nbsp;s | β⁻ (98.57%) | ¹⁴⁹Ce | rowspan=2|(3/2−) | rowspan=2| | rowspan=2| |- | β⁻, n (1.43%) | ¹⁴⁸Ce |-id=Lanthanum-150 | rowspan=2|¹⁵⁰La | rowspan=2 style="text-align:right" | 57 | rowspan=2 style="text-align:right" | 93 | rowspan=2|149.9395475(27) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/150.pdf 1993] | rowspan=2|504(15)&nbsp;ms | β⁻ (97.3%) | ¹⁵⁰Ce | rowspan=2|(3+) | rowspan=2| | rowspan=2| |- | β⁻, n (2.7%) | ¹⁴⁹Ce |-id=Lanthanum-151 | ¹⁵¹La | style="text-align:right" | 57 | style="text-align:right" | 94 | 150.94277(47) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/151.pdf 1994] | 465(24)&nbsp;ms | β⁻ | ¹⁵¹Ce | 1/2+# | | |-id=Lanthanum-152 | ¹⁵²La | style="text-align:right" | 57 | style="text-align:right" | 95 | 151.94709(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/152.pdf 1994] | 287(16)&nbsp;ms | β⁻ | ¹⁵²Ce | 2−# | | |-id=Lanthanum-153 | ¹⁵³La | style="text-align:right" | 57 | style="text-align:right" | 96 | 152.95055(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/153.pdf 1994] | 245(18)&nbsp;ms | β⁻ | ¹⁵³Ce | 1/2+# | | |-id=Lanthanum-154 | ¹⁵⁴La | style="text-align:right" | 57 | style="text-align:right" | 97 | 153.95542(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/154.pdf 2017] | 161(15)&nbsp;ms | β⁻ | ¹⁵⁴Ce | 2−# | | |-id=Lanthanum-155 | ¹⁵⁵La | style="text-align:right" | 57 | style="text-align:right" | 98 | 154.95928(43)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/155.pdf 2017] | 101(28)&nbsp;ms | β⁻ | ¹⁵⁵Ce | 1/2+# | | |-id=Lanthanum-156 | ¹⁵⁶La | style="text-align:right" | 57 | style="text-align:right" | 99 | 155.96452(43)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/156.pdf 2017] | 84(78)&nbsp;ms | β⁻ | ¹⁵⁶Ce | 4+# | | |-id=Lanthanum-157 | ¹⁵⁷La | style="text-align:right" | 57 | style="text-align:right" | 100 | 156.96879(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/157.pdf 2018] | 30#&nbsp;ms{{br}}[>&nbsp;550&nbsp;ns] | | | 1/2+# | | |-id=Lanthanum-158 | ¹⁵⁸La<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" | 57 | style="text-align:right" | 101 | | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/57/158.pdf 2026] | | | | | | {{Isotopes table/footer}}

== See also == '''Daughter products other than lanthanum''' * Isotopes of cerium * Isotopes of barium * Isotopes of caesium

== References == {{reflist}} * Isotope masses from: ** {{NUBASE 2003}} * Isotopic compositions and standard atomic masses from: ** {{CIAAW2003}} ** {{CIAAW 2005}} * Half-life, spin, and isomer data selected from the following sources. ** {{NUBASE 2003}} ** {{NNDC}} ** {{CRC85|chapter=11}}

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Category:Isotopes of lanthanum Category:Lanthanum Lanthanum