135Ba
135Ba is a radioactive isotope of the element barium with mass number 135. It is one of several isotopes of barium and is not a stable nuclide. The nucleus contains 56 protons and 79 neutrons.
135Ba is neutron-rich relative to the line of beta stability and decays primarily by beta minus emission
135Ba is produced in nuclear environments, particularly as a fission product in reactors and during irradiation
Natural, stable barium does not contain 135Ba in appreciable amounts; any measurable 135Ba in the environment