No, beta decay is not a form of nuclear fission. Beta decay occurs when a neutron in the nucleus of an atom decays into a proton, emitting a beta particle (an electron or positron) and a neutrino or antineutrino. In contrast, nuclear fission is the process of splitting a large atomic nucleus (such as those of uranium or plutonium) into smaller nuclei by bombarding it with neutrons, releasing a large amount of energy in the process.
