The atom is formed like solar system. Surrounding this energy center there whirl, in endless profusion but in fluctuating circuits, the energy units which are faintly comparable to the planets encircling a sun.  When electrons pass from higher to lower energy levels of orbital revolution, quanta are always given off. 
Calcium easily loses its outermost electron and moves the previous one thousands of times between its orbit and that of the lost electron. With these juggling with electrons the atom is able to partially defy gravity and get fired with the emanations of sunlight. 
While gravity is one of several factors concerned in holding together a tiny atomic energy system, there is also present in and among these basic physical units a powerful and unknown energy, the secret of their basic constitution and ultimate behavior, a force which remains to be discovered on Urantia. 
The charged protons and the uncharged neutrons of the nucleus of the atom are held together by the reciprocating function of the mesotron, a particle of matter 180 times as heavy as the electron.  Atom stability depends on number of inactive neutrons. 
Annihilation of atoms is principle source of solar energy.  Atoms broken up at 35,000,000°F, the electronic boiling point.  All of the phenomena of atom building and atom dissolution are attended by the emergence of flood tides of short space rays of radiant energy.  Gamma rays characterize spontaneous dissociation of atoms. 
The first twenty-seven atoms, those containing from one to twenty-seven orbital electrons, are more easy of comprehension than the rest. From twenty-eight upward we encounter more and more of the unpredictability of the supposed presence of the Unqualified Absolute. 
Subsequent to greater progress and further discoveries, after we have advanced immeasurably in comparison with present knowledge, though we should gain control of the energy revolutions of the electrical units of matter to the extent of modifying their physical manifestations—even after all such possible progress, forever will scientists be powerless to create one atom of matter or to originate one flash of energy or ever to add to matter that which we call life.