Americium-242

Overview
Americium-242 is a radioactive isotope of Americium with 95 protons and electrons and 147 neutrons and a mass of 242.0595492 g/mol. It has a half-life of approximately 141 years. It either decays by isomeric transition (with a decay energy is 0.05MeV), by spontaneous fission, or by emitting an alpha particle (the decay energy is 5.64 MeV) to turn into Neptunium-238).