As I understand it, in all forms of radioactive decay, constrained by E=mc^2, a spontaneous breakdown of an element or isotope occurs: that is, a massive element (parent) decays to a less massive element, isotope or leptons [daughter(s)], plus a release of energy. However, in alpha decay, the energy release, unless understood as binding or potential energy, is not apparent in the end product accounting (see example below). Whereas in gamma decay, the energy release in the form of a high-energy photon is. But, unless I consider gamma decay as the end stage of alpha or beta decay, where the nucleus is often left in an excited state, I don't see the little bit of matter in the break away end products. Only in beta decay do I explicitly see both the break away of a small bit of matter and energy release; a neutron turns into a proton or a proton turns into a neutron, plus an electron and other leptons with an energy release in the form of kinetic energy associated with the movement of the electron. Is it correct to say that binding energy is the small bit of missing mass of the bounded parent (mass deficit) as compared to the total of the unbounded masses of the parent's constituents (nucleons) free from the nucleus? While I think this is correct, I found an explanation of both alpha and beta decay that says the opposite: "Energy is released in the process of alpha [and beta] decay. Careful measurements show that the sum of the masses of the daughter nucleus and the alpha [beta particle] is a bit less than the mass of the parent isotope. ...the mass that is lost in such decay is converted into kinetic energy and carried away by the decay products." Moreover, given that protons and neutrons are also in motion all the time, kinetic energy must be somehow involved in all nuclear reactions not just in radioactive decay. And since nuclear potential energy is stored energy inside nuclei which is a measure of the work done to bind protons to protons, neutrons to neutrons?, and protons to neutrons, it too must be somehow involved in all nuclear reactions. Example: In alpha decay, the element uranium (92U238) decays to an isotope of thorium (90Th234) + 2He4 (alpha particle). A little bit of matter (the tightly bound helium nucleus breaks away from the unstable uranium element , it decays to a thorium isotope which itself is unstable so decay continues until a stable isotope is produced. Unless the binding energy is fleeting existing only during the process or lost in the rounding, I don't find it when during an accounting of the mass in alpha decay. In the decay of uranium (92U238 --> 90Th234 + 2He4), all the mass is accounted for without allocating any mass to energy in the end products; if binding energy is involved, it seems only so in terms of its mass equivalent but not explicitly as energy per se.