A couple of really stupid questions:( In beta minus decay, an atom release and electron (and an antineutrino). The electron, does this happen spontaneously? Doesn't the another particle have to collide or interact with the atom (be give it some momentum, or energy), to trigger the atom to release an electron. And in beta plus decay, an atom releases a positron. Where does this positron actually come from? The atom can liberate electrons, sure, but not positrons!