Virtually all the mass of the atom resides in the nucleus. The nucleus is held together by the tight pull of what is known to Physicists as the Strong force. This force between the nucleons overcomes the repulsive electrical force that would push the protons apart. Chemical interactions are essentially electron interactions of two atoms. The magnitude of the charge on an electron is equal to the charge on a protron.
Electrons surround the atom in pathways called orbitals.
The inner orbitals surrounding the atom are spherical but the outer orbitals are much more complicated. Chemical Bonding Chemically bonding occurs when two particles can exchange or combine their outer electrons in such a way that is energetically favorable .