In that situation the atoms will attract the other's electrons with about the same strength, and it will take a similar amount of energy to remove an electron from each atom. If we have a metal/metal or a nonmetal/nonmetal pairing then each atom in the pair will have a similar electronegativity and ionization energy as the atom it is bonded with.If two atoms are going to bond together we have three possible categories:.Non-Metals (high ionization energy and high electronegativity).Metals (low ionization energy and low electronegativity).The periodic table can be divided into two broad groups:.Basically, atoms are most stable when they can achieve an outer electron structure similar to the closest Noble gas.This can be done by either sharing electrons between atoms, taking electrons from other atoms, or giving electrons away to other atoms. If atoms don't have 8 valence electrons (or two if they are close to He), then they will react with other atoms in order to have 8 valence electrons.One exception is He which has a full principle energy level with 2 electrons. All of these elements have 8 valence electrons in their highest principle energy level.
Periodic Table and Bonding: Valence Electrons Valence Electrons