Isotopes of cerium explained

Naturally occurring cerium (₅₈Ce) is composed of 4 stable isotopes: ¹³⁶Ce, ¹³⁸Ce, ¹⁴⁰Ce, and ¹⁴²Ce, with ¹⁴⁰Ce being the most abundant (88.48% natural abundance) and the only one theoretically stable; ¹³⁶Ce, ¹³⁸Ce, and ¹⁴²Ce are predicted to undergo double beta decay but this process has never been observed. There are 35 radioisotopes that have been characterized, with the most stable being ¹⁴⁴Ce, with a half-life of 284.893 days; ¹³⁹Ce, with a half-life of 137.640 days and ¹⁴¹Ce, with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 10 meta states.

The isotopes of cerium range in atomic weight from 119 u (¹¹⁹Ce) to 157 u (¹⁵⁷Ce).

List of isotopes

|-| ¹¹⁹Ce| style="text-align:right" | 58| style="text-align:right" | 61| 118.95276(64)#| 200# ms| β⁺| ¹¹⁹La| 5/2+#|||-| ¹²⁰Ce| style="text-align:right" | 58| style="text-align:right" | 62| 119.94664(75)#| 250# ms| β⁺| ¹²⁰La| 0+|||-| ¹²¹Ce| style="text-align:right" | 58| style="text-align:right" | 63| 120.94342(54)#| 1.1(1) s| β⁺| ¹²¹La| (5/2)(+#)|||-| rowspan=2|¹²²Ce| rowspan=2 style="text-align:right" | 58| rowspan=2 style="text-align:right" | 64| rowspan=2|121.93791(43)#| rowspan=2|2# s| β⁺| ¹²²La| rowspan=2|0+| rowspan=2|| rowspan=2||-| β⁺, p| ¹²¹Ba|-| rowspan=2|¹²³Ce| rowspan=2 style="text-align:right" | 58| rowspan=2 style="text-align:right" | 65| rowspan=2|122.93540(32)#| rowspan=2|3.8(2) s| β⁺| ¹²³La| rowspan=2|(5/2)(+#)| rowspan=2|| rowspan=2||-| β⁺, p| ¹²²Ba|-| ¹²⁴Ce| style="text-align:right" | 58| style="text-align:right" | 66| 123.93041(32)#| 9.1(12) s| β⁺| ¹²⁴La| 0+|||-| rowspan=2|¹²⁵Ce| rowspan=2 style="text-align:right" | 58| rowspan=2 style="text-align:right" | 67| rowspan=2|124.92844(21)#| rowspan=2|9.3(3) s| β⁺| ¹²⁵La| rowspan=2|(7/2−)| rowspan=2|| rowspan=2||-| β⁺, p| ¹²⁴Ba|-| ¹²⁶Ce| style="text-align:right" | 58| style="text-align:right" | 68| 125.92397(3)| 51.0(3) s| β⁺| ¹²⁶La| 0+|||-| ¹²⁷Ce| style="text-align:right" | 58| style="text-align:right" | 69| 126.92273(6)| 29(2) s| β⁺| ¹²⁷La| 5/2+#|||-| ¹²⁸Ce| style="text-align:right" | 58| style="text-align:right" | 70| 127.91891(3)| 3.93(2) min| β⁺| ¹²⁸La| 0+|||-| ¹²⁹Ce| style="text-align:right" | 58| style="text-align:right" | 71| 128.91810(3)| 3.5(3) min| β⁺| ¹²⁹La| (5/2+)|||-| ¹³⁰Ce| style="text-align:right" | 58| style="text-align:right" | 72| 129.91474(3)| 22.9(5) min| β⁺| ¹³⁰La| 0+|||-| style="text-indent:1em" | ^130mCe| colspan="3" style="text-indent:2em" | 2453.6(3) keV| 100(8) ns||| (7−)|||-| ¹³¹Ce| style="text-align:right" | 58| style="text-align:right" | 73| 130.91442(4)| 10.2(3) min| β⁺| ¹³¹La| (7/2+)|||-| style="text-indent:1em" | ^131mCe| colspan="3" style="text-indent:2em" | 61.8(1) keV| 5.0(10) min| β⁺| ¹³¹La| (1/2+)|||-| ¹³²Ce| style="text-align:right" | 58| style="text-align:right" | 74| 131.911460(22)| 3.51(11) h| β⁺| ¹³²La| 0+|||-| style="text-indent:1em" | ^132mCe| colspan="3" style="text-indent:2em" | 2340.8(5) keV| 9.4(3) ms| IT| ¹³²Ce| (8−)|||-| ¹³³Ce| style="text-align:right" | 58| style="text-align:right" | 75| 132.911515(18)| 97(4) min| β⁺| ¹³³La| 1/2+|||-| style="text-indent:1em" | ^133mCe| colspan="3" style="text-indent:2em" | 37.1(8) keV| 4.9(4) d| β⁺| ¹³³La| 9/2−|||-| ¹³⁴Ce| style="text-align:right" | 58| style="text-align:right" | 76| 133.908925(22)| 3.16(4) d| EC| ¹³⁴La| 0+|||-| ¹³⁵Ce| style="text-align:right" | 58| style="text-align:right" | 77| 134.909151(12)| 17.7(3) h| β⁺| ¹³⁵La| 1/2(+)|||-| style="text-indent:1em" | ^135mCe| colspan="3" style="text-indent:2em" | 445.8(2) keV| 20(1) s| IT| ¹³⁵Ce| (11/2−)|||-| ¹³⁶Ce| style="text-align:right" | 58| style="text-align:right" | 78| 135.907172(14)| colspan=3 align=center|Observationally Stable^[1] | 0+| 0.00185(2)| 0.00185–0.00186|-| style="text-indent:1em" | ^136mCe| colspan="3" style="text-indent:2em" | 3095.5(4) keV| 2.2(2) μs||| 10+|||-| ¹³⁷Ce| style="text-align:right" | 58| style="text-align:right" | 79| 136.907806(14)| 9.0(3) h| β⁺| ¹³⁷La| 3/2+| | |-| rowspan=2 style="text-indent:1em" | ^137mCe| rowspan=2 colspan="3" style="text-indent:2em" | 254.29(5) keV| rowspan=2|34.4(3) h| IT (99.22%)| ¹³⁷Ce| rowspan=2|11/2−| rowspan=2|| rowspan=2||-| β⁺ (.779%)| ¹³⁷La|-| ¹³⁸Ce| style="text-align:right" | 58| style="text-align:right" | 80| 137.905991(11)| colspan=3 align=center|Observationally Stable^[2] | 0+| 0.00251(2)| 0.00251–0.00254|-| style="text-indent:1em" | ^138mCe| colspan="3" style="text-indent:2em" | 2129.17(12) keV| 8.65(20) ms| IT| ¹³⁸Ce| 7-|||-| ¹³⁹Ce| style="text-align:right" | 58| style="text-align:right" | 81| 138.906653(8)| 137.641(20) d| EC| ¹³⁹La| 3/2+|||-| style="text-indent:1em" | ^139mCe| colspan="3" style="text-indent:2em" | 754.24(8) keV| 56.54(13) s| IT| ¹³⁹Ce| 11/2−|||-| ¹⁴⁰Ce^[3] | style="text-align:right" | 58| style="text-align:right" | 82| 139.9054387(26)| colspan=3 align=center|Stable| 0+| 0.88450(51)| 0.88446–0.88449|-| style="text-indent:1em" | ^140mCe| colspan="3" style="text-indent:2em" | 2107.85(3) keV| 7.3(15) μs||| 6+|||-| ¹⁴¹Ce| style="text-align:right" | 58| style="text-align:right" | 83| 140.9082763(26)| 32.508(13) d| β⁻| ¹⁴¹Pr| 7/2−|||-| ¹⁴²Ce| style="text-align:right" | 58| style="text-align:right" | 84| 141.909244(3)| colspan=3 align=center|Observationally Stable^{[4] [5]} | 0+| 0.11114(51)| 0.11114–0.11114|-| ¹⁴³Ce| style="text-align:right" | 58| style="text-align:right" | 85| 142.912386(3)| 33.039(6) h| β⁻| ¹⁴³Pr| 3/2−|||-| ¹⁴⁴Ce| style="text-align:right" | 58| style="text-align:right" | 86| 143.913647(4)| 284.91(5) d| β⁻| ^144mPr| 0+|||-| ¹⁴⁵Ce| style="text-align:right" | 58| style="text-align:right" | 87| 144.91723(4)| 3.01(6) min| β⁻| ¹⁴⁵Pr| (3/2−)|||-| ¹⁴⁶Ce| style="text-align:right" | 58| style="text-align:right" | 88| 145.91876(7)| 13.52(13) min| β⁻| ¹⁴⁶Pr| 0+|||-| ¹⁴⁷Ce| style="text-align:right" | 58| style="text-align:right" | 89| 146.92267(3)| 56.4(10) s| β⁻| ¹⁴⁷Pr| (5/2−)|||-| ¹⁴⁸Ce| style="text-align:right" | 58| style="text-align:right" | 90| 147.92443(3)| 56(1) s| β⁻| ¹⁴⁸Pr| 0+|||-| ¹⁴⁹Ce| style="text-align:right" | 58| style="text-align:right" | 91| 148.9284(1)| 5.3(2) s| β⁻| ¹⁴⁹Pr| (3/2−)#|||-| ¹⁵⁰Ce| style="text-align:right" | 58| style="text-align:right" | 92| 149.93041(5)| 4.0(6) s| β⁻| ¹⁵⁰Pr| 0+|||-| ¹⁵¹Ce| style="text-align:right" | 58| style="text-align:right" | 93| 150.93398(11)| 1.02(6) s| β⁻| ¹⁵¹Pr| 3/2−#|||-| ¹⁵²Ce| style="text-align:right" | 58| style="text-align:right" | 94| 151.93654(21)#| 1.4(2) s| β⁻| ¹⁵²Pr| 0+|||-| ¹⁵³Ce| style="text-align:right" | 58| style="text-align:right" | 95| 152.94058(43)#| 500# ms [>300 ns]| β⁻| ¹⁵³Pr| 3/2−#|||-| ¹⁵⁴Ce| style="text-align:right" | 58| style="text-align:right" | 96| 153.94342(54)#| 300# ms [>300 ns]| β⁻| ¹⁵⁴Pr| 0+|||-| ¹⁵⁵Ce| style="text-align:right" | 58| style="text-align:right" | 97| 154.94804(64)#| 200# ms [>300 ns]| β⁻| ¹⁵⁵Pr| 5/2−#|||-| ¹⁵⁶Ce| style="text-align:right" | 58| style="text-align:right" | 98| 155.95126(64)#| 150# ms| β⁻| ¹⁵⁶Pr| 0+|||-| ¹⁵⁷Ce| style="text-align:right" | 58| style="text-align:right" | 99| 156.95634(75)#| 50# ms| β⁻| ¹⁵⁷Pr| 7/2+#||

References

• Isotope masses from:
  • • Isotopic compositions and standard atomic masses from:
      • • Half-life, spin, and isomer data selected from the following sources.

Notes and References

1. Theorized to undergo β⁺β⁺ decay to ¹³⁶Ba with a half-life over 38×10¹⁵ years
2. Theorized to undergo β⁺β⁺ decay to ¹³⁸Ba with a half-life over 150×10¹² years
3. [Fission product]
4. Theorized to undergo β⁻β⁻ decay to ¹⁴²Nd or α decay to ¹³⁸Ba with a half-life over 2.9×10¹⁸ years
5. Belli . P. . Bernabei . R. . Danevich . F. A. . Incicchitti . A. . Tretyak . V. I. . Experimental searches for rare alpha and beta decays . 2019 . . 55 . 140 . 4–6 . 10.1140/epja/i2019-12823-2. 1908.11458 . 2019EPJA...55..140B . 254103706 .