Isotopes of berkelium#Berkelium-251
{{Short description|none}}
{{Infobox berkelium isotopes}}
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 known is 247Bk with a half-life of 1,380 years; however 248Bk, which has not been observed to decay, may live longer.
List of isotopes
{{Anchor|Berkelium-235|Berkelium-237|Berkelium-250m3|Berkelium-254}}
{{Isotopes table
|symbol=Bk
|refs=NUBASE2020, AME2020 II
|notes=m, unc(), mass#, exen#, spin(), spin#, SF, EC
}}
|-id=Berkelium-233
| 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
|-id=Berkelium-234
| 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?{{cite journal|last1=Kaji|first1=D.|last2=Morimoto|first2=K.|last3=Haba|first3=H.|last4=Ideguchi|first4=E.|last5=Koura|first5=H.|last6=Morita|first6=K.|date=2016|title=Decay Properties of New Isotopes 234Bk and 230Am, and Even–Even Nuclides 234Cm and 230Pu|url=https://www.researchgate.net/publication/291009584|format=PDF|journal=Journal of the Physical Society of Japan|volume=84|issue=15002|pages=015002|doi=10.7566/JPSJ.85.015002|bibcode=2016JPSJ...85a5002K }}
| (various)
|-id=Berkelium-236
| 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
|-id=Berkelium-238
| 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
|-id=Berkelium-239
| 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)
|-id=Berkelium-240
| 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
|-id=Berkelium-241
| 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
|-id=Berkelium-242
| 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
|-id=Berkelium-242m
| 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
|-id=Berkelium-243
| 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
|-id=Berkelium-244
| 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
|-id=Berkelium-244m
| 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
|-id=Berkelium-245
| 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
|-id=Berkelium-246
| 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
|-id=Berkelium-247
| 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)
|-id=Berkelium-248
| 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
|-id=Berkelium-248m
| rowspan=3 style="text-indent:1em" | 248mBk{{r|g=n|OGI|r=Order of ground state and isomer is uncertain.}}
| 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
|-id=Berkelium-249
| 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)
|-id=Berkelium-249m
| style="text-indent:1em" | 249mBk
| colspan="3" style="text-indent:2em" | 8.777(14) keV
| 300 μs
| IT
| 249Bk
| 3/2−
|-id=Berkelium-250
| 250Bk
| style="text-align:right" | 97
| style="text-align:right" | 153
| 250.0783172(31)
| 3.212(5) h
| β−
| 250Cf
| 2−
|-id=Berkelium-250m1
| style="text-indent:1em" | 250m1Bk
| colspan="3" style="text-indent:2em" | 35.59(10) keV
| 29(1) μs
| IT
| 250Bk
| 4+
|-id=Berkelium-250m2
| style="text-indent:1em" | 250m2Bk
| colspan="3" style="text-indent:2em" | 85.6(16) keV
| 213(8) μs
| IT
| 250Bk
| 7+
|-id=Berkelium-251
| 251Bk
| style="text-align:right" | 97
| style="text-align:right" | 154
| 251.080761(12)
| 55.6(11) min
| β−
| 251Cf
| (3/2−)
|-id=Berkelium-251m
| style="text-indent:1em" | 251mBk
| colspan="3" style="text-indent:2em" | 35.5(13) keV
| 58(4) μs
| IT
| 251Bk
| (7/2+)
|-id=Berkelium-252
| 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
|-id=Berkelium-253
| 253Bk
| style="text-align:right" | 97
| style="text-align:right" | 156
| 253.08688(39)#
| 60# min
| β−?
| 253Cf
| 3/2-#
{{Isotopes table/footer}}
Actinides vs fission products
{{Actinides vs fission products}}
{{clear}}
References
{{Reflist}}
- Isotope masses from:
- {{NUBASE 2003}}
- Half-life, spin, and isomer data selected from the following sources.
- {{NUBASE 2003}}
- {{NNDC}}
- {{CRC85|chapter=11}}
{{Navbox element isotopes}}