The adjective atomic, although synonymous with nuclear when modifying energy and weapons, is quite distinct from nuclear when modifying energy level and physics. The difference is in the portion of the atom that is being described. Nuclear exclusively denotes the dynamics of particles associated with the core of an atom, including the protons and neutrons. This is where most of the mass of an atom is located. Thus, the nuclear binding energy between a neutron and proton in deuterium (an isotope of hydrogen) is 1.2 million electron volts. Atomic, when not synonymous with nuclear, denotes the dynamics of particles associated with the outer layers of the atom, the electrons. It is the configuration of electrons that determines the chemistry of an atom. Thus, the atomic binding energy of an electron in deuterium is 13.6 electron volts, a factor approximately 100,000 times smaller than the nuclear binding energy.
