Radioactivity and Types of Decay

Some nuclei are unstable and spontaneously transform into other nuclei, emitting radiation in the process. This phenomenon is called radioactivity, and it was discovered by Henri Becquerel and studied extensively by Marie and Pierre Curie. Radioactive decay is a random and spontaneous process: it is impossible to predict when any individual nucleus will decay, and the decay is unaffected by external conditions such as temperature, pressure, or chemical bonding. The nucleus decays because it is energetically favorable, moving toward a more stable configuration. There are three principal types of nuclear radiation, named after the first three letters of the Greek alphabet: alpha, beta, and gamma.

Alpha ($\alpha$) radiation consists of alpha particles, which are helium-4 nuclei, written $^{4}