Isotopes of lanthanum explained

Naturally occurring lanthanum (57La) is composed of one stable (139La) and one radioactive (138La) isotope, with the stable isotope, 139La, being the most abundant (99.91% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being 138La, with a half-life of 1.02×1011 years; 137La, with a half-life of 60,000 years and 140La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 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 isotopes of lanthanum range in atomic weight from 115.96 u (116La) to 154.96 u (155La).

List of isotopes

|-| rowspan=2|116La[1] | rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 59| rowspan=2|| rowspan=2|50(22) ms| p (~60%)| 115Ba| rowspan=2|| rowspan=2|| rowspan=2||-| β+ (~40%)| 116Ba|-| rowspan=2|117La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 60| rowspan=2|116.95007(43)#| rowspan=2|23.5(26) ms| β+| 117Ba| rowspan=2|(3/2+, 3/2−)| rowspan=2|| rowspan=2||-| p| 116Ba|-| style="text-indent:1em" | 117mLa| colspan="3" style="text-indent:2em" | 151(12) keV| 10(5) ms||| (9/2+)|||-| 118La| style="text-align:right" | 57| style="text-align:right" | 61| 117.94673(32)#| 200# ms| β+| 118Ba||||-| 119La| style="text-align:right" | 57| style="text-align:right" | 62| 118.94099(43)#| 1# s| β+| 119Ba| 11/2−#|||-| rowspan=2|120La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 63| rowspan=2|119.93807(54)#| rowspan=2|2.8(2) s| β+| 120Ba| rowspan=2|| rowspan=2|| rowspan=2||-| β+, p| 119Cs|-| rowspan=2|121La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 64| rowspan=2|120.93301(54)#| rowspan=2|5.3(2) s| β+| 121Ba| rowspan=2|11/2−#| rowspan=2|| rowspan=2||-| β+, p| 120Cs|-| rowspan=2|122La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 65| rowspan=2|121.93071(32)#| rowspan=2|8.6(5) s| β+| 122Ba| rowspan=2|| rowspan=2|| rowspan=2||-| β+, p| 121Cs|-| 123La| style="text-align:right" | 57| style="text-align:right" | 66| 122.92624(21)#| 17(3) s| β+| 123Ba| 11/2−#|||-| 124La| style="text-align:right" | 57| style="text-align:right" | 67| 123.92457(6)| 29.21(17) s| β+| 124Ba| (7−, 8−)|||-| style="text-indent:1em" | 124mLa| colspan="3" style="text-indent:2em" | 100(100)# keV| 21(4) s||| low(+#)|||-| 125La| style="text-align:right" | 57| style="text-align:right" | 68| 124.920816(28)| 64.8(12) s| β+| 125Ba| (11/2−)|||-| style="text-indent:1em" | 125mLa| colspan="3" style="text-indent:2em" | 107.0(10) keV| 390(40) ms||| (3/2+)|||-| 126La| style="text-align:right" | 57| style="text-align:right" | 69| 125.91951(10)| 54(2) s| β+| 126Ba| (5)(+#)|||-| style="text-indent:1em" | 126mLa| colspan="3" style="text-indent:2em" | 210(410) keV| 20(20) s||| (0−, 1−, 2−)|||-| 127La| style="text-align:right" | 57| style="text-align:right" | 70| 126.916375(28)| 5.1(1) min| β+| 127Ba| (11/2−)|||-| rowspan=2 style="text-indent:1em" | 127mLa| rowspan=2 colspan="3" style="text-indent:2em" | 14.8(12) keV| rowspan=2|3.7(4) min| β+| 127Ba| rowspan=2|(3/2+)| rowspan=2|| rowspan=2||-| IT| 127La|-| 128La| style="text-align:right" | 57| style="text-align:right" | 71| 127.91559(6)| 5.18(14) min| β+| 128Ba| (5+)|||-| style="text-indent:1em" | 128mLa| colspan="3" style="text-indent:2em" | 100(100)# keV| <1.4 min| IT| 128La| (1+, 2−)|||-| 129La| style="text-align:right" | 57| style="text-align:right" | 72| 128.912693(22)| 11.6(2) min| β+| 129Ba| 3/2+|||-| style="text-indent:1em" | 129mLa| colspan="3" style="text-indent:2em" | 172.1(4) keV| 560(50) ms| IT| 129La| 11/2−|||-| 130La| style="text-align:right" | 57| style="text-align:right" | 73| 129.912369(28)| 8.7(1) min| β+| 130Ba| 3(+)|||-| 131La| style="text-align:right" | 57| style="text-align:right" | 74| 130.91007(3)| 59(2) min| β+| 131Ba| 3/2+|||-| style="text-indent:1em" | 131mLa| colspan="3" style="text-indent:2em" | 304.52(24) keV| 170(10) μs||| 11/2−|||-| 132La| style="text-align:right" | 57| style="text-align:right" | 75| 131.91010(4)| 4.8(2) h| β+| 132Ba| 2−|||-| rowspan=2 style="text-indent:1em" | 132mLa| rowspan=2 colspan="3" style="text-indent:2em" | 188.18(11) keV| rowspan=2|24.3(5) min| IT (76%)| 132La| rowspan=2|6−| rowspan=2|| rowspan=2||-| β+ (24%)| 132Ba|-| 133La| style="text-align:right" | 57| style="text-align:right" | 76| 132.90822(3)| 3.912(8) h| β+| 133Ba| 5/2+|||-| 134La| style="text-align:right" | 57| style="text-align:right" | 77| 133.908514(21)| 6.45(16) min| β+| 134Ba| 1+|||-| 135La| style="text-align:right" | 57| style="text-align:right" | 78| 134.906977(11)| 19.5(2) h| β+| 135Ba| 5/2+|||-| 136La| style="text-align:right" | 57| style="text-align:right" | 79| 135.90764(6)| 9.87(3) min| β+| 136Ba| 1+|||-| style="text-indent:1em" | 136mLa| colspan="3" style="text-indent:2em" | 255(9) keV| 114(3) ms| IT| 136La| (8)(−#)|||-| 137La| style="text-align:right" | 57| style="text-align:right" | 80| 136.906494(14)| 6(2)×104 y| EC| 137Ba| 7/2+||| extinct|-| rowspan=2|138La[2] | rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 81| rowspan=2|137.907112(4)| rowspan=2|1.02(1)×1011 y| β+ (66.4%)| 138Ba| rowspan=2|5+| rowspan=2|9.0(1)×10−4| rowspan=2||-| β− (33.6%)| 138Ce|-| style="text-indent:1em" | 138mLa| colspan="3" style="text-indent:2em" | 72.57(3) keV| 116(5) ns||| (3)+|||-| 139La[3] | style="text-align:right" | 57| style="text-align:right" | 82| 138.9063533(26)| colspan=3 align=center|Stable| 7/2+| 0.99910(1)||-| 140La| style="text-align:right" | 57| style="text-align:right" | 83| 139.9094776(26)| 1.6781(3) d| β−| 140Ce| 3−|||-| 141La| style="text-align:right" | 57| style="text-align:right" | 84| 140.910962(5)| 3.92(3) h| β−| 141Ce| (7/2+)|||-| 142La| style="text-align:right" | 57| style="text-align:right" | 85| 141.914079(6)| 91.1(5) min| β−| 142Ce| 2−|||-| 143La| style="text-align:right" | 57| style="text-align:right" | 86| 142.916063(17)| 14.2(1) min| β−| 143Ce| (7/2)+|||-| 144La| style="text-align:right" | 57| style="text-align:right" | 87| 143.91960(5)| 40.8(4) s| β−| 144Ce| (3−)|||-| 145La| style="text-align:right" | 57| style="text-align:right" | 88| 144.92165(10)| 24.8(20) s| β−| 145Ce| (5/2+)|||-| rowspan=2|146La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 89| rowspan=2|145.92579(8)| rowspan=2|6.27(10) s| β− (99.99%)| 146Ce| rowspan=2|2−| rowspan=2|| rowspan=2||-| β−, n (.007%)| 145Ce|-| style="text-indent:1em" | 146mLa| colspan="3" style="text-indent:2em" | 130(130) keV| 10.0(1) s| β−| 146Ce| (6−)|||-| rowspan=2|147La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 90| rowspan=2|146.92824(5)| rowspan=2|4.015(8) s| β− (99.96%)| 147Ce| rowspan=2|(5/2+)| rowspan=2|| rowspan=2||-| β−, n (.04%)| 146Ce|-| rowspan=2|148La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 91| rowspan=2|147.93223(6)| rowspan=2|1.26(8) s| β− (99.85%)| 148Ce| rowspan=2|(2−)| rowspan=2|| rowspan=2||-| β−, n (.15%)| 147Ce|-| rowspan=2|149La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 92| rowspan=2|148.93473(34)#| rowspan=2|1.05(3) s| β− (98.6%)| 149Ce| rowspan=2|5/2+#| rowspan=2|| rowspan=2||-| β−, n (1.4%)| 148Ce|-| rowspan=2|150La| rowspan=2 style="text-align:right" | 57| rowspan=2 style="text-align:right" | 93| rowspan=2|149.93877(43)#| rowspan=2|510(30) ms| β− (97.3%)| 150Ce| rowspan=2|(3+)| rowspan=2|| rowspan=2||-| β−, n (2.7%)| 149Ce|-| 151La| style="text-align:right" | 57| style="text-align:right" | 94| 150.94172(43)#| 300# ms [>300&nbsp;ns]| β−| 151Ce| 5/2+#|||-| 152La| style="text-align:right" | 57| style="text-align:right" | 95| 151.94625(43)#| 200# ms [>300&nbsp;ns]| β−| 152Ce||||-| 153La| style="text-align:right" | 57| style="text-align:right" | 96| 152.94962(64)#| 150# ms [>300&nbsp;ns]| β−| 153Ce| 5/2+#|||-| 154La| style="text-align:right" | 57| style="text-align:right" | 97| 153.95450(64)#| 100# ms| β−| 154Ce||||-| 155La| style="text-align:right" | 57| style="text-align:right" | 98| 154.95835(86)#| 60# ms| β−| 155Ce| 5/2+#||

References

  1. Zhang . Wei . Cederwall . Bo . Aktas . Özge . Liu . Xiaoyu . Ertoprak . Aysegül . Nyberg . Ayse . Auranen . Kalle . Alayed . Betool . Badran . Hussam . Boston . Helen . Doncel . Maria . Forsberg . Ulrika . Grahn . Tuomas . Greenlees . Paul T. . Guo . Song . Heery . Jacob . Hilton . Joshua . Jenkins . David . Julin . Rauno . Juutinen . Sakari . Luoma . Minna . Neuvonen . Olavi . Ojala . Joonas . Page . Robert D. . Pakarinen . Janne . Partanen . Jari . Paul . Edward S. . Petrache . Costel . Rahkila . Panu . Ruotsalainen . Panu . Sandzelius . Mikael . Sarén . Jan . Szwec . Stuart . Tann . Holly . Uusitalo . Juha . Wadsworth . Robert . Observation of the proton emitter . Communications Physics . 14 November 2022 . 5 . 1 . 1–8 . 10.1038/s42005-022-01069-w . 253512231 . 2399-3650. free .
  2. [primordial nuclide|Primordial]
  3. [Fission product]

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