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Isotopes of radium

Radium (88Ra) has no stable or nearly stable isotopes, and thus a standard atomic weight cannot be given. The longest lived, and most common, isotope of radium is 226Ra with a half-life of 1600 years. 226Ra occurs in the decay chain of 238U (often referred to as the radium series). Radium has 34 known isotopes from 201Ra to 234Ra.

In 2013 it was discovered that the nucleus of radium-224 is pear-shaped.[2] This was the first discovery of an asymmetrical nucleus.

List of isotopes

  1. ^ mRa – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ Modes of decay:
  5. ^ Bold symbol as daughter – Daughter product is stable.
  6. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  8. ^ Intermediate decay product of 237Np
  9. ^ Lightest known nuclide to undergo cluster decay
  10. ^ Used for treating bone cancer
  11. ^ Intermediate decay product of 235U
  12. ^ a b Intermediate decay product of 232Th
  13. ^ Intermediate decay product of 237Np
  14. ^ Source of element's name
  15. ^ Theoretically capable of β-β- decay to 226Th[1]
  16. ^ Intermediate decay product of 238U

Actinides vs fission products

References

  1. ^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ "First observations of short-lived pear-shaped atomic nuclei". 28 November 2023.
  3. ^ a b Kalaninová, Z.; Antalic, S.; Andreyev, A. N.; Heßberger, F. P.; Ackermann, D.; Andel, B.; Bianco, L.; Hofmann, S.; Huyse, M.; Kindler, B.; Lommel, B.; Mann, R.; Page, R. D.; Sapple, P. J.; Thomson, J.; Van Duppen, P.; Venhart, M. (12 May 2014). "Decay of 201–203Ra and 200–202Fr" (PDF). Physical Review C. 89 (5): 054312. Bibcode:2014PhRvC..89e4312K. doi:10.1103/PhysRevC.89.054312. ISSN 0556-2813. Retrieved 11 June 2023.
  4. ^ Uusitalo, J.; Leino, M.; Enqvist, T.; Eskola, K.; Grahn, T.; Greenlees, P. T.; Jones, P.; Julin, R.; Juutinen, S.; Keenan, A.; Kettunen, H.; Koivisto, H.; Kuusiniemi, P.; Leppänen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P.; Scholey, C. (11 February 2005). "α decay studies of very neutron-deficient francium and radium isotopes". Physical Review C. 71 (2): 024306. Bibcode:2005PhRvC..71b4306U. doi:10.1103/PhysRevC.71.024306. ISSN 0556-2813.
  5. ^ Liang, C. F.; Paris, P.; Sheline, R. K. (2000-09-19). "α decay of 225Ra". Physical Review C. 62 (4). American Physical Society (APS): 047303. Bibcode:2000PhRvC..62d7303L. doi:10.1103/physrevc.62.047303. ISSN 0556-2813.
  6. ^ 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.
  7. ^ Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor.
  8. ^ 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. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4.
    "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 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
  9. ^ This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
  10. ^ 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 eight quadrillion years.