barium136

Barium-136 is a stable isotope of the element barium (Z = 56). It consists of 56 protons and 80 neutrons, giving it a mass number of 136. Like other stable, even-even nuclei, its ground state has nuclear spin 0 and positive parity.

Ba-136 is one of the naturally occurring isotopes of barium. In nature, it accounts for a significant fraction of elemental barium, with a natural abundance on the order of several percent (approximately 7–8%).

As a stable isotope, Ba-136 does not undergo radioactive decay under normal conditions. It has no radioactive decay mode that would be observed in typical samples, and its half-life is effectively infinite.

Ba-136 is formed and maintained in stellar nucleosynthesis, primarily through slow neutron capture (the s-process) in asymptotic giant branch stars. This process contributes to the isotopic composition of heavy elements in the universe, including barium, before the material is dispersed into the interstellar medium.

Applications of Ba-136 arise mainly in geochemical and cosmochemical studies, where isotopic compositions help constrain models of nucleosynthesis, planetary differentiation, and dating. In laboratory settings, barium isotopes are used in mass spectrometry and as part of isotopic reference materials, though Ba-133 and related radioisotopes are more prominent in radiological applications.

Safety considerations for handling barium compounds apply regardless of the isotope: soluble barium compounds are toxic if ingested or inhaled, so appropriate precautions are required.