Isotopes of barium

Naturally occurring <a href="/facts/Barium/IkL09XHQ">barium</a> (56Ba) is a mix of six stable <a href="/facts/Isotope/KD9B1y6o">isotopes</a> and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001. This nuclide decays by <a href="/facts/Double_electron_capture/aQ1ElH3c">double electron capture</a> (absorbing two electrons and emitting two neutrinos), with a half-life of (0.5–2.7)×1021 years (about 1011 times the age of the universe).
There are a total of thirty-three known <a href="/facts/Radioisotope/5WpCfbdq">radioisotopes</a> in addition to 130Ba. The longest-lived of these is 133Ba, which has a half-life of 10.51 years. All other radioisotopes have half-lives shorter than two weeks. The longest-lived <a href="/facts/Nuclear_isomer/L8DHcqnk">isomer</a> is 133mBa, which has a half-life of 38.9 hours. The shorter-lived 137mBa (half-life 2.55 minutes) arises as the decay product of the common fission product <a href="/facts/Caesium-137/NrY5Tb6j">caesium-137</a>.
Barium-114 is predicted to undergo <a href="/facts/Cluster_decay/sIelGo3t">cluster decay</a>, emitting a nucleus of stable <a href="/facts/Carbon-12/nJYECzEr">12C</a> to produce 102Sn. However this decay is not yet observed; the upper limit on the branching ratio of such decay is 0.0034%.

Isotopes of barium open-in-new

Isotopes of barium