Physics:Isotopes of berkelium
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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 20 known radioisotopes, from 230Bk and 233Bk to 253Bk (with the exception of 235Bk and 237Bk), and 6 nuclear isomers. The longest-lived isotope is 247Bk with a half-life of 1,380 years.
List of isotopes
Nuclide [n 1] |
Z | N | Isotopic mass (u) [n 2][n 3] |
Half-life |
Decay mode [n 4] |
Daughter isotope |
Spin and parity [n 5][n 6] |
---|---|---|---|---|---|---|---|
Excitation energy[n 6] | |||||||
230Bk[2] | 97 | 133 | ~0.46 s | α | 226Am | ||
233Bk[3] | 97 | 136 | 21+48 −17 s |
α | 229Am | 3/2-# | |
234Bk[4] | 97 | 137 | 19+6 −4 s |
β+ | 234Cm | 3-# | |
β+, SF | (various) | ||||||
α | 230Am | ||||||
236Bk[5] | 97 | 139 | 236.05733(43)# | 22+13 −6 s |
β+ (96%) | 236Cm | 4+# |
β+, SF (4%) | (various) | ||||||
238Bk | 97 | 141 | 238.05828(31)# | 2.40(8) min | β+ | 238Cm | 1# |
β+, SF (0.048%) | (various) | ||||||
α (rare) | 234Am | ||||||
239Bk[6] | 97 | 142 | 239.05828(25)# | 100# s | β+ (>99%) | 239Cm | (7/2+) |
α (<1%) | 235Am | ||||||
SF (<1%) | (various) | ||||||
240Bk | 97 | 143 | 240.05976(16)# | 4.8(8) min | β+ | 240Cm | 7-# |
β+, SF (0.002%) | (various) | ||||||
α (rare) | 236Am | ||||||
241Bk[7] | 97 | 144 | 241.06023(22)# | 4.6(4) min | β+ | 241Cm | (7/2+) |
α (rare) | 237Am | ||||||
242Bk | 97 | 145 | 242.06198(22)# | 7.0(13) min | β+ | 242Cm | 2−# |
β+, SF (<3×10−5%) | (various) | ||||||
242mBk | 200(200)# keV | 600(100) ns | SF | (various) | |||
243Bk | 97 | 146 | 243.063008(5) | 4.5(2) h | β+ (99.85%) | 243Cm | (3/2−) |
α (.15%) | 239Am | ||||||
244Bk | 97 | 147 | 244.065181(16) | 4.35(15) h | β+ (99.99%) | 244Cm | (4−)# |
α (.006%) | 240Am | ||||||
245Bk | 97 | 148 | 245.0663616(25) | 4.94(3) d | EC (99.88%) | 245Cm | 3/2− |
α (.12%) | 241Am | ||||||
246Bk | 97 | 149 | 246.06867(6) | 1.80(2) d | EC (99.8%) | 246Cm | 2(−) |
α (.2%) | 242Am | ||||||
247Bk | 97 | 150 | 247.070307(6) | 1.38(25)×103 y | α | 243Am | (3/2−) |
SF (rare) | (various) | ||||||
248Bk | 97 | 151 | 248.07309(8)# | >300 y[8] | α | 244Am | 6+# |
248mBk | 30(70)# keV | 23.7(2) h | β− | 248Cf | 1(−) | ||
249Bk[n 7] | 97 | 152 | 249.0749867(28) | 330(4) d | β− | 249Cf | 7/2+ |
α (.00145%) | 245Am | ||||||
SF (4.7×10−8%) | (various) | ||||||
249mBk | 8.80(10) keV | 300 μs | IT | 249Bk | (3/2−) | ||
250Bk | 97 | 153 | 250.078317(4) | 3.212(5) h | β− | 250Cf | 2− |
250m1Bk | 35.59(5) keV | 29(1) μs | IT | 250Bk | (4+) | ||
250m2Bk | 84.1(21) keV | 213(8) μs | (7+) | ||||
251Bk | 97 | 154 | 251.080760(12) | 55.6(11) min | β− | 251Cf | (3/2−)# |
α (10−5%) | 247Am | ||||||
251mBk | 35.5(13) keV | 58(4) μs | IT | 251Bk | (7/2+)# | ||
252Bk | 97 | 155 | 252.08431(22)# | 1.8(5) min | β− | 252Cf | |
α | 248Am | ||||||
253Bk | 97 | 156 | 253.08688(39)# | 10# min | β− | 253Cf |
- ↑ mBk – Excited nuclear isomer.
- ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ↑
Modes of decay:
EC: Electron capture SF: Spontaneous fission - ↑ ( ) spin value – Indicates spin with weak assignment arguments.
- ↑ 6.0 6.1 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ↑ Easiest isotope to synthesize
Actinides vs fission products
Actinides and fission products by half-life
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---|---|---|---|---|---|---|---|---|
Actinides[9] by decay chain | Half-life range (y) |
Fission products of 235U by yield<ref>Specifically from thermal neutron fission of U-235, e.g. in a typical nuclear reactor.</ref> | ||||||
4n | 4n+1 | 4n+2 | 4n+3 | |||||
4.5–7% | 0.04–1.25% | <0.001% | ||||||
228Ra№ | 4–6 | † | 155Euþ | |||||
244Cmƒ | 241Puƒ | 250Cf | 227Ac№ | 10–29 | 90Sr | 85Kr | 113mCdþ | |
232Uƒ | 238Puƒ | 243Cmƒ | 29–97 | 137Cs | 151Smþ | 121mSn | ||
248Bk[10] | 249Cfƒ | 242mAmƒ | 141–351 |
No fission products | ||||
241Amƒ | 251Cfƒ[11] | 430–900 | ||||||
226Ra№ | 247Bk | 1.3 k – 1.6 k | ||||||
240Pu | 229Th | 246Cmƒ | 243Amƒ | 4.7 k – 7.4 k | ||||
245Cmƒ | 250Cm | 8.3 k – 8.5 k | ||||||
239Puƒ | 24.1 k | |||||||
230Th№ | 231Pa№ | 32 k – 76 k | ||||||
236Npƒ | 233Uƒ | 234U№ | 150 k – 250 k | ‡ | 99Tc₡ | 126Sn | ||
248Cm | 242Pu | 327 k – 375 k | 79Se₡ | |||||
1.53 M | 93Zr | |||||||
237Npƒ | 2.1 M – 6.5 M | 135Cs₡ | 107Pd | |||||
236U | 247Cmƒ | 15 M – 24 M | 129I₡ | |||||
244Pu | 80 M |
... nor beyond 15.7 M years[12] | ||||||
232Th№ | 238U№ | 235Uƒ№ | 0.7 G – 14.1 G | |||||
Legend for superscript symbols |
See also
References
- ↑ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4.
- ↑ Heinz, Sophie. "Observation of new neutron-deficient multinucleon transfer reactions isotopes with Z ≥ 92 in multinucleon transfer reactions". GSI Helmholtzzentrum and Justus-Liebig-Universität Gießen. https://slideplayer.com/slide/9789996/.
- ↑ Devaraja, H. M.; Heinz, S.; Beliuskina, O.; Comas, V.; Hofmann, S.; Hornung, C.; Münzenberg, G.; Nishio, K. et al. (2 September 2015). "Observation of new neutron-deficient isotopes with Z≥92 in multinucleon transfer reactions" (in en). Physics Letters B 748: 199–203. doi:10.1016/j.physletb.2015.07.006. ISSN 0370-2693. Bibcode: 2015PhLB..748..199D. https://jopss.jaea.go.jp/pdfdata/AA2015-0304.pdf. Retrieved 23 June 2023.
- ↑ 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. doi:10.7566/JPSJ.85.015002. Bibcode: 2016JPSJ...85a5002K. https://www.researchgate.net/publication/291009584.
- ↑ Konki, J. (10 Jan 2017). "Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk". Physics Letters B 764: 265–270. doi:10.1016/j.physletb.2016.11.038. ISSN 0370-2693. Bibcode: 2017PhLB..764..265K.
- ↑ Antalic, S.Expression error: Unrecognized word "et". (2010). "Studies of neutron-deficient mendelevium isotopes at SHIP". European Physical Journal A 43 (1): 35–44. doi:10.1140/epja/i2009-10896-0. Bibcode: 2010EPJA...43...35A.
- ↑ Asai, M.; Tsukada, K.; Ichikawa, S.; Sakama, M.; Haba, H.; Nagame, Y.; Nishinaka, I.; Akiyama, K. et al. (1 January 2003). "Identification of the new isotope 241Bk" (in en). The European Physical Journal A - Hadrons and Nuclei 16 (1): 17–19. doi:10.1140/epja/i2002-10112-y. ISSN 1434-601X. Bibcode: 2003EPJA...16...17A. https://link.springer.com/content/pdf/10.1140/epja/i2002-10112-y.pdf. Retrieved 25 June 2023.
- ↑ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4. Bibcode: 1965NucPh..71..299M.
- ↑ Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
- ↑ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4. Bibcode: 1965NucPh..71..299M.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 y. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 y. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 y." - ↑ This is the heaviest nuclide with a half-life of at least four years before the "Sea of Instability".
- ↑ Excluding those "classically stable" nuclides with half-lives significantly in excess of 232Th; e.g., while 113mCd has a half-life of only fourteen years, that of 113Cd is nearly eight quadrillion years.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A 729: 3–128, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- Isotopic compositions and standard atomic masses from:
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051.
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A 729: 3–128, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/.
- Lide, David R., ed (2004). "11. Table of the Isotopes". CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
Original source: https://en.wikipedia.org/wiki/Isotopes of berkelium.
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