Other Radioactive Processes. While the most common types of radioactive decay are by alpha, beta, and gamma radiation, several other varieties of radioactivity occur: Electron capture: A parent nucleus may capture one of its own electrons and emit a neutrino.This is exhibited in the potassium-argon decay.he process leaves a vacancy in the electron energy level from which the electron came, and that vacancy is either filled by the dropping down of a higher-level electron with the emission of an X-ray or by the ejection of an outer electron in a process called the Auger effect.