All atomic nuclei of the chemical element berkelium are summarized under berkelium isotopes; these consist of an atomic nucleus with 97 protons and in the uncharged state of 97 electrons. The difference between the individual berkelium isotopes lies in the number of neutrons in the nucleus.
243Berkelium is a chemical element from the actinide group, first produced and verified in 1949 as part of artificial nuclear processes.
All of the unstable, radioactive, 20 known isotopes of berkelium are created in nuclear reactors, for example from the nuclear reaction between americium and helium nuclei or by irradiation of plutonium-239 with neutrons. Any small traces of the element in nature can be attributed to neutron capture by uranium nuclei. Bk-247 has the longest half-life of 1380 years.
Technically, the nuclides of Berkelium have no meaning - outside of nuclear research.
| Isotope Nuclide | E | N | Atomic Mass [Nuclear Mass] {Mass Excess} | Spin I (h/2π) | Parent |
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 |
| Berkelium-233 | 23397Bk | 136 | 233.05675(24) u [233.0035453 u] {52.86228 MeV} | ||
| Berkelium-234 | 23497Bk | 137 | 234.05739(15) u [234.0041853 u] {53.45844 MeV} | ||
| Berkelium-235 | 23597Bk | 138 | |||
| Berkelium-236 | 23697Bk | 139 | 236.05748(43) u [236.0042753 u] {53.54228 MeV} | (4+) | |
| Berkelium-237 | 23797Bk | 140 | |||
| Berkelium-238 | 23897Bk | 141 | 238.05820(27) u [238.0049953 u] {54.21295 MeV} | ||
| Berkelium-239 | 23997Bk | 142 | 239.05824(22) u [239.0050353 u] {54.25021 MeV} | (3/2-,7/2+) | |
| Berkelium-240 | 24097Bk | 143 | 240.05976(16) u [240.0065553 u] {55.66608 MeV} | 244Es | |
| Berkelium-241 | 24197Bk | 144 | 241.06015(21) u [241.0069453 u] {56.02936 MeV} | (7/2+) | 245Es |
| Berkelium-242 | 24297Bk | 145 | 242.06198(21) u [242.0087753 u] {57.734 MeV} | 246Es | |
| Berkelium-242m1 | 242m197Bk | 145 | 242.06198(21) u [242.0087753 u] {57.734 MeV} | ||
| Berkelium-242m2 | 242m297Bk | 145 | 242.06198(21) u [242.0087753 u] {57.734 MeV} | ||
| Berkelium-243 | 24397Bk | 146 | 243.063006(5) u [243.0098013 u] {58.68971 MeV} | (3/2-) | 247Es 243Cf |
| Berkelium-244 | 24497Bk | 147 | 244.065179(15) u [244.0119743 u] {60.71385 MeV} | (4-) | 248Es |
| Berkelium-245 | 24597Bk | 148 | 245.0663599(19) u [245.0131552 u] {61.81385 MeV} | 3/2- | 249Es 245Cf |
| Berkelium-246 | 24697Bk | 149 | 246.06867(6) u [246.0154653 u] {63.96569 MeV} | 2(-) | 246Cf |
| Berkelium-247 | 24797Bk | 150 | 247.070306(6) u [247.0171013 u] {65.48962 MeV} | 3/2- | 251Es 247Cf |
| Berkelium-248 | 24897Bk | 151 | 248.07309(8) u [248.0198853 u] {68.0829 MeV} | (6+,8-) | 252Es |
| Berkelium-248m | 248m97Bk | 151 | 248.07309(8) u [248.0198853 u] {68.0829 MeV} | 1(-) | |
| Berkelium-249 | 24997Bk | 152 | 249.0749832(13) u [249.0217785 u] {69.8464 MeV} | 7/2+ | 253Es 249Cm |
| Berkelium-249m | 249m97Bk | 152 | 249.0749832(13) u [249.0217785 u] {69.8464 MeV} | 3/2- | |
| Berkelium-250 | 25097Bk | 153 | 250.078315(4) u [250.0251103 u] {72.94995 MeV} | 2- | 254Es |
| Berkelium-250m1 | 250m197Bk | 153 | 250.078315(4) u [250.0251103 u] {72.94995 MeV} | (4+) | |
| Berkelium-250m2 | 250m297Bk | 153 | 250.078315(4) u [250.0251103 u] {72.94995 MeV} | (7+) | |
| Berkelium-251 | 25197Bk | 154 | 251.080761(12) u [251.0275563 u] {75.22839 MeV} | (3/2-) | 255Es 251Cm |
| Berkelium-251m | 251m97Bk | 154 | 251.080761(12) u [251.0275563 u] {75.22839 MeV} | (7/2+) | |
| Berkelium-252 | 25297Bk | 155 | 252.08431(21) u [252.0311053 u] {78.53426 MeV} | ||
| Berkelium-253 | 25397Bk | 156 | 253.08688(38) u [253.0336753 u] {80.9282 MeV} | ||
| Berkelium-254 | 25497Bk | 157 |
| Isotope | Radioactive Decay | Extern | |||
|---|---|---|---|---|---|
| Half-life | Decay Mode | Probability | Energy | ||
| 7 | 8 | 9 | 10 | 11 | 12 |
| Bk-233 | 21(+48-17) s | α → 229Am EC/β+ → 233Cm | ca. 82 % ca. 18 % | 8.29(21) MeV 5.57(24) MeV | AL |
| Bk-234 | ca. 140 s | α → 230Am EC → 234Cm | ≥ 80 % ≤ 20 % | 8.10(5) MeV 6.73(14) MeV | AL |
| Bk-235 | - ungelistet - | AL | |||
| Bk-236 | 22(+13-6) s | EC/β+ → 236Cm EC, SF div | 96 % 4(2) % | 5.69(40) MeV | AL |
| Bk-237 | - ungelistet - | AL | |||
| Bk-238 | 144(5) s | EC/β+ → 238Cm EC, F | 99.952 % 0.048(20) % | 4.77(26) MeV | AL |
| Bk-239 | EC → 239Cm α → 235Am SF div | > 99 % < 1 % < 1 % | 3.10(21) MeV 7.20(20) MeV | AL | |
| Bk-240 | 4.8(8) min | EC/β+ → 240Cm EC/SF div | ? 0.0020(13) % | 3.95(15) MeV | AL |
| Bk-241 | 4.6(4) min | EC/β+ → 241Cm α → 237Am | ? ? | 2.33(20) MeV 7.04(21) MeV | AL |
| Bk-242 | 7.0(13) min | EC/β+ → 242Cm | ≤ 100 % | 2.93(20) MeV | AL |
| Bk-242m1 | 600(100) ns | SF div | ≤ 100 % | AL | |
| Bk-242m2 | 9.5(20) ns | SF div | ≤ 100 % | AL | |
| Bk-243 | 4.5(2) h | EC/β+ → 243Cm α → 239Am | 99.85 % 0.15 % | 1.508(5) MeV 6.874(4) MeV | AL |
| Bk-244 | 5.03(2) h | EC/β+ → 244Cm α → 240Am | 99.994(3) % 0.006(3) % | 2.262(14) MeV 6.779(4) MeV | AL |
| Bk-245 | 4.95(3) d | EC → 245Cm α → 241Am | 99.88(1) % 0.12(1) % | 0.8093(21) MeV 6.4545(14) MeV | AL |
| Bk-246 | 1.80(2) d | EC/β+ → 246Cm | 100 % | 1.350(60) MeV | AL |
| Bk-247 | 1380(250) a | α → 243Am | ≤ 100 % | 5.890(5) MeV | AL |
| Bk-248 | > 9 a | AL | |||
| Bk-248m | 23.7(2) h | β- → 248Cf EC/β+ → 248Cm | 70(5) % 30(5) % | AL | |
| Bk-249 | 330(4) d | β- → 249Cf α → 245Am SF div | 99.99855(8) % 0.00145(8) % Spuren | 0.1236(4) MeV 5.5210(14) MeV | AL |
| Bk-249m | 0.3 ms | AL | |||
| Bk-250 | 3.212(5) h | β- → 250Cf | 100 % | 1.780(3) MeV | AL |
| Bk-250m1 | 29(1) μs | ||||
| Bk-250m2 | 213(8) μs | ||||
| Bk-251 | 55.6(11) min | β- → 251Cf | 100 % | 1.093(10) MeV | AL |
| Bk-251m | 58(4) μs | ||||
| Bk-252 | ca. 2 min | AL | |||
| Bk-253 | 10 min | AL | |||
| Bk-254 | - ungelistet - | AL | |||
Notes (related to the columns):
1 - name of the nuclide, isotope.
2 - E: isotope symbol with mass number (superscript; number of nucleons) and Atomic number (subscript; number of protons).
3 - N: number of neutrons.
4 - relative atomic mass of the Berkelium isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
5 - nuclear spin I, unit: h/2π.
6 - source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
7 - isotope notation in short form.
8 - decay: half-live of the Berkelium isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
9 - decay mode: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
10 - decay probability in percent (%).
11 - decay energy; Particle energy related to decay type.
12 - other information and notes: AL = Adopted Levels (link to external data [1]).
Miscellaneous:
()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
- unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.
According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Berkelium radionuclides:
| Nuclide | Limit Value | HASS limit | SC | Daughter Nuclides | Half-life | |
|---|---|---|---|---|---|---|
| Bk-245 | 106 Bq | 100 Bq/g | 4.9 d | |||
| Bk-246+ | 106 Bq | 10 Bq/g | 1.8 d | |||
| Bk-247 | 104 Bq | 0,1 Bq/g | 0,08 TBq | 1400 a | ||
| Bk-249+ | 106 Bq | 100 Bq/g | 10 Bq cm-2 | 320.0 d | ||
| Bk-250 | 106 Bq | 10 Bq/g | 3.2 h | |||
(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)
Properties of the Berkelium nucleides
[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.
[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.
[3] - Live Chart of Nuclides. Nuclear structure and decay data.
Berkelium: NMR properties
[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.
[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.
[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.
[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).
More sources:
[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.
[9] - L. B. Magnusson et al.:
Berkelium and Californium Isotopes Produced in Neutron Irradiation of Plutonium.
In: Physical Review, (1954), DOI 10.1103/PhysRev.96.1576.
[10] - E. K. Hulet:
New Isotope of Berkelium.
In: Physical Review, (1956), DOI 10.1103/PhysRev.102.182.
[11] - T. A. Eastwood, J. P. Butler, M. J. Cabell, H. G. Jackson:
Isotopes of Berkelium and Californium Produced by Neutron Irradiation of Plutonium.
In: Physical Review, (1957), DOI 10.1103/PhysRev.107.1635.
[12] - Valentin N. Kosyakov:
Perspective methods for Berkelium-249 preparation and application.
In: Journal of Nuclear Science and Technology, (2002), DOI 10.1080/00223131.2002.10875405.
[13] - Daiya Kaji et al.:
Decay Properties of New Isotopes 234Bk and 230Am, and Even-Even Nuclides 234Cm and 230Pu.
In: Journal of the Physical Society of Japan, (2015), DOI 10.7566/JPSJ.85.015002.
Last update: 2022-12-05
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