Isotopes of berkelium explained

Berkelium (₉₇Bk) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁴³Bk in 1949. There are twenty known radioisotopes, from ²³³Bk and ²³³Bk to ²⁵³Bk (except ²³⁵Bk and ²³⁷Bk), and six nuclear isomers. The longest-lived isotope is ²⁴⁷Bk with a half-life of 1,380 years.

List of isotopes

|-| rowspan=2|²³³Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 136| rowspan=2|233.05665(25)#| rowspan=2|40(30) s| α| ²²⁹Am| rowspan=2|3/2-#|-| β⁺?| ²³³Cm|-| rowspan=3|²³⁴Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 137| rowspan=3|234.05732(16)#| rowspan=3|20(5) s| α (>80%)| ²³⁰Am| rowspan=3|3-#|-| β⁺ (<20%)| ²³⁴Cm|-| β⁺, SF?^[1] | (various)|-| rowspan=3|²³⁶Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 139| rowspan=3|236.05748(39)#| rowspan=3|26(10) s| β⁺ (99.96%)| ²³⁶Cm| rowspan=2|4+#|-| β⁺, SF (0.04%)| (various)|-| α?| ²³²Am|-| rowspan=3|²³⁸Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 141| rowspan=3|238.05820(28)#| rowspan=3|2.40(8) min| β⁺ (99.95%)| ²³⁸Cm| rowspan=3| 1#|-| β⁺, SF (0.048%)| (various)|-| α?| ²³⁴Am|-| rowspan=3|²³⁹Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 142| rowspan=3|239.05824(22)#| rowspan=3|100# s| β⁺| ²³⁹Cm| rowspan=3|(7/2+)|-| α?| ²³⁵Am|-| SF?| (various)|-| rowspan=3|²⁴⁰Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 143| rowspan=3|240.05976(16)#| rowspan=3|4.8(8) min| β⁺?| ²⁴⁰Cm| rowspan=3|7−#|-| β⁺, SF (0.0020%)| (various)|-| α?| ²³⁶Am|-| rowspan=2|²⁴¹Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 144| rowspan=2|241.06010(18)#| rowspan=2|4.6(4) min| β⁺?| ²⁴¹Cm| rowspan=2|(7/2+)|-| α?| ²³⁷Am|-| rowspan=3|²⁴²Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 145| rowspan=3|242.06198(22)#| rowspan=3|7.0(13) min| β⁺| ²⁴²Cm| rowspan=3|3+#|-| β⁺, SF (<3×10⁻⁵%)| (various)|-| α?| ²³⁸Am|-| rowspan=2 style="text-indent:1em" | ^242mBk| rowspan=2 colspan="3" style="text-indent:2em" | 2000(200)# keV| rowspan=2|600(100) ns| SF| (various)| rowspan=2||-| IT?| ²⁴²Bk|-| rowspan=2|²⁴³Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 146| rowspan=2|243.0630059(49)| rowspan=2|4.6(2) h| β⁺ (99.85%)| ²⁴³Cm| rowspan=2|3/2−|-| α (.15%)| ²³⁹Am|-| rowspan=2|²⁴⁴Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 147| rowspan=2|244.065179(15)| rowspan=2|5.02(3) h| β⁺?| ²⁴⁴Cm| rowspan=2|4−|-| α (0.006%)| ²⁴⁰Am|-| rowspan=2 style="text-indent:1em" | ^244mBk| rowspan=2 colspan="3" style="text-indent:2em" | 1500(500)# keV| rowspan=2|820(60) ns| SF| (various)| rowspan=2||-| IT?| ²⁴⁴Bk|-| rowspan=2|²⁴⁵Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 148| rowspan=2|245.0663598(19)| rowspan=2|4.95(3) d| EC (99.88%)| ²⁴⁵Cm| rowspan=2|3/2−|-| α (.12%)| ²⁴¹Am|-| rowspan=2|²⁴⁶Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 149| rowspan=2|246.068671(64)| rowspan=2|1.80(2) d| β⁺| ²⁴⁶Cm| rowspan=2|2(−)|-| α?| ²⁴²Am|-| rowspan=2|²⁴⁷Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 150| rowspan=2|247.0703059(56)| rowspan=2|1.38(25)×10³ y| α| ²⁴³Am| rowspan=2|3/2−|-| SF?| (various)|-| rowspan=2|²⁴⁸Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 151| rowspan=2|248.073142(54)| rowspan=2|>9 y| α?| ²⁴⁴Am| rowspan=2|6+#|-| EC?| ²⁴⁸Cm|-| rowspan=3 style="text-indent:1em" | ^248mBk| rowspan=3 colspan="3" style="text-indent:2em" | −20(50) keV| rowspan=3| 23.7(2) h| β⁻ (70%)| ²⁴⁸Cf| rowspan=3| 1(−)|-| EC (30%)| ²⁴⁸Cm|-| α?| ²⁴⁴Am|-| rowspan=3|²⁴⁹Bk| rowspan=3 style="text-align:right" | 97| rowspan=3 style="text-align:right" | 152| rowspan=3|249.0749831(13)| rowspan=3|327.2(3) d| β⁻| ²⁴⁹Cf| rowspan=3|7/2+|-| α (.00145%)| ²⁴⁵Am|-| SF (4.7×10⁻⁸%)| (various)|-| style="text-indent:1em" | ^249mBk| colspan="3" style="text-indent:2em" | 8.777(14) keV| 300 μs| IT| ²⁴⁹Bk| 3/2−|-| ²⁵⁰Bk| style="text-align:right" | 97| style="text-align:right" | 153| 250.0783172(31)| 3.212(5) h| β⁻| ²⁵⁰Cf| 2−|-| style="text-indent:1em" | ^250m1Bk| colspan="3" style="text-indent:2em" | 35.59(10) keV| 29(1) μs| IT| ²⁵⁰Bk| 4+|-| style="text-indent:1em" | ^250m2Bk| colspan="3" style="text-indent:2em" | 85.6(16) keV| 213(8) μs| IT| ²⁵⁰Bk| 7+|-| ²⁵¹Bk| style="text-align:right" | 97| style="text-align:right" | 154| 251.080761(12)| 55.6(11) min| β⁻| ²⁵¹Cf| (3/2−)|-| style="text-indent:1em" | ^251mBk| colspan="3" style="text-indent:2em" | 35.5(13) keV| 58(4) μs| IT| ²⁵¹Bk| (7/2+)|-| rowspan=2|²⁵²Bk| rowspan=2 style="text-align:right" | 97| rowspan=2 style="text-align:right" | 155| rowspan=2|252.08431(22)#| rowspan=2|1.8(5) min| β⁻?| ²⁵²Cf| rowspan=2||-| α?| ²⁴⁸Am|-| ²⁵³Bk| style="text-align:right" | 97| style="text-align:right" | 156| 253.08688(39)#| 60# min| β⁻?| ²⁵³Cf| 3/2-#

Actinides vs fission products

References

1. Kaji. D.. Morimoto. K.. Haba. H.. Ideguchi. E.. Koura. H.. Morita. K.. 2016. Decay Properties of New Isotopes ²³⁴Bk and ²³⁰Am, and Even–Even Nuclides ²³⁴Cm and ²³⁰Pu. PDF. Journal of the Physical Society of Japan. 84. 15002. 015002. 10.7566/JPSJ.85.015002. 2016JPSJ...85a5002K .

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