Isotopes of radium

Isotopes of radium (88Ra)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
223Ra trace 11.435 d α 219Rn
224Ra trace 3.632 d α 220Rn
225Ra trace 14.8 d β− 225Ac
α[2] 221Rn
Preview warning: Infobox Ra isotopes: Decay mode not recognised, input shown unedited "dm2=α" cat#D
226Ra trace 1600 y α 222Rn
228Ra trace 5.75 y β− 228Ac

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, which is in the decay chain of 238U (the uranium or radium series).

Radium now has 34 known isotopes from 201Ra to 234Ra.

In the early history of the study of radioactivity, the different natural isotopes of radium were given different names (as were those of other radioactive elements), as it was not until Frederick Soddy's scientific work in the 1900s and 1910s that the concept of isotopes was employed.[3] In this scheme, 223Ra was named actinium X (AcX), 224Ra thorium X (ThX), 226Ra radium (Ra), and 228Ra mesothorium 1 (MsTh1).[4] When it was realized that all of these are isotopes of the same element, many of these names fell out of use, and "radium" came to refer to all isotopes, not just 226Ra,[5] though mesothorium 1 in particular was still used for some time, with a footnote explaining that it referred to 228Ra.[6] The known decay products of radium-226 received historical names including "radium",[7] starting with radium emanation and then ranging from radium A to radium G, with the letter indicating approximately how far they were down the chain from their parent.[a]

In 2013 it was discovered that the nucleus of radium-224 is pear-shaped.[9] This was the first discovery of an asymmetrical nucleus.

  1. ^ 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. ^ 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.
  3. ^ Nagel, Miriam C. (September 1982). "Frederick Soddy: From alchemy to isotopes". Journal of Chemical Education. 59 (9): 739. Bibcode:1982JChEd..59..739N. doi:10.1021/ed059p739. ISSN 0021-9584.
  4. ^ Kirby, H.W. & Salutsky, Murrell L. (December 1964). The Radiochemistry of Radium (Report). crediting UNT Libraries Government Documents Department. p. 3 – via University of North Texas, UNT Digital Library. Alternate source: https://sgp.fas.org/othergov/doe/lanl/lib-www/books/rc000041.pdf
  5. ^ Giunta, Carmen J. (2017). "ISOTOPES: IDENTIFYING THE BREAKTHROUGH PUBLICATION (1)" (PDF). Bull. Hist. Chem. 42 (2): 103–111.
  6. ^ Looney, William B. (1958). "Effects of Radium in Man". Science. 127 (3299): 630–633. Bibcode:1958Sci...127..630L. doi:10.1126/science.127.3299.630. ISSN 0036-8075. JSTOR 1755774. PMID 13529029.
  7. ^ Mitchell, S. A. "Is Radium in the Sun?". Popular Astronomy. 21: 321–331. Bibcode:1913PA.....21..321M.
  8. ^ Kuhn, W. (1929). "LXVIII. Scattering of thorium C" γ-radiation by radium G and ordinary lead". The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. 8 (52): 628. doi:10.1080/14786441108564923. ISSN 1941-5982.
  9. ^ Hills, Stephanie (8 May 2013). "First observations of short-lived pear-shaped atomic nuclei". CERN.


Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).

This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.