Isotopes of berkelium

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Berkelium (Bk) has no stable isotopes. A standard atomic mass cannot be given.

[edit] Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
235Bk 97 138 235.05658(43)# 20# s
236Bk 97 139 236.05733(43)# 1# min
237Bk 97 140 237.05700(24)# 1# min 7/2+#
238Bk 97 141 238.05828(31)# 2.40(8) min
239Bk 97 142 239.05828(25)# 3# min 7/2+#
240Bk 97 143 240.05976(16)# 4.8(8) min
241Bk 97 144 241.06023(22)# 4.6(4) min (7/2+)
242Bk 97 145 242.06198(22)# 7.0(13) min 2-#
242mBk 200(200)# keV 600(100) ns
243Bk 97 146 243.063008(5) 4.5(2) h (3/2-)
244Bk 97 147 244.065181(16) 4.35(15) h (4-)#
245Bk 97 148 245.0663616(25) 4.94(3) d 3/2-
246Bk 97 149 246.06867(6) 1.80(2) d 2(-)
247Bk 97 150 247.070307(6) 1.38(25)E+3 a (3/2-)
248Bk 97 151 248.07309(8)# >9 a 6+#
248mBk 30(70)# keV 23.7(2) h 1(-)
249Bk 97 152 249.0749867(28) 330(4) d 7/2+
249mBk 8.80(10) keV 300 µs (3/2-)
250Bk 97 153 250.078317(4) 3.212(5) h 2-
250m1Bk 35.59(5) keV 29(1) µs (4+)
250m2Bk 84.1(21) keV 213(8) µs (7+)
251Bk 97 154 251.080760(12) 55.6(11) min (3/2-)#
251mBk 35.5(13) keV 58(4) µs (7/2+)#
252Bk 97 155 252.08431(22)# 1.8(5) min
253Bk 97 156 253.08688(39)# 10# min
254Bk 97 157 254.09060(32)# 1# min

[edit] Notes

  • Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
  • Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

[edit] References


Isotopes of curium Isotopes of berkelium Isotopes of californium
Index to isotope pages