Since the total mass energy can be emitted as radiation, and the atom is an orbital system, this can occur only in case every particle in the system is traveling in its orbit at the velocity of light with a zero mass. It follows that the entropy increase is from a negative infinity to a final value of zero. When this occurs, in theory, no further adjustments are possible. Now we must consider the mechanism of radiation from an atom. As long as an electron in a quantum orbit maintains that orbit, no radiation occurs.
Radiation is emitted when the electron moves to lower orbit.
This, in turn, will affect lower orbits to cause transitions to occur. The final state is that in which all planetary electrons are ingested by the nucleus. When this occurs, all nuclear protons are bred to neutrons. Since the nucleus thus collapses under the action of spin forces, in the ideal case, a virtual infinity of mesons with extremely high velocities are emitted. In the process of fusion, binding energies are increased.