Covalent Bonding

Covalent Bonding can be complicated. It involves atoms combining to share electrons and attempting to attain an octet, or set of eight electrons. Nonmetals usually form covalent bonds, and the electron affinities of the different atoms need to be very close in order for the atoms not to make ions.  For example, to make a hydrogen molecule, two hydrogen atoms must come together. (Hydrogen of course being an exception to the octet rule, as it has only one energy level, but its the same idea.) When these atoms come together, they share their respective electrons to form a molecule, H2. For the bond to be the strongest, the two atoms need to be at a distance that allows the forces of attraction and the force of repulsion between the two atoms to be in a proportion that will keep the atoms together.