Atoms are attracted to each other because they are made of charged particles. An atom's protons not only hold onto its own electrons, they also tug on the electrons of other atoms. This Powerpoint presentation explores the tug of war over valence electrons that occurs between atoms. The possible outcomes are discussed, culminating with an example of ionic bonding between sodium and chlorine. Bohr diagrams are used to analyze the results of the electron transfers, showing the complete outer shell of both the cation and the anion, and explaining the charges of each.
Free worksheets on this topic are available on my website at http://evanschemistrycorner.com.