As we shall explore in this section on ionic bonding, ionic bonds result from the mutual attraction between oppositely charged ions. They tend to be stronger than covalent bonds due to the coulombic attraction between ions of opposite charges. To maximize the attraction between those ions, ionic compounds form crystal lattices of alternating cations and anions. Ionic compounds are usually formed only between atoms whose difference in electronegativity is large.
In our description of ionic bonding, we will explore the questions of what determines the bond length and bond strength of an ionic bond. We will show that bonds form at particular distances even though the attraction between oppositely charged ions increases strongly with decreasing distance. The opposing strong internuclear repulsion maintains the separation between ions. Bond strength, it will be shown, depends mostly on the charges present on each ion and the distance between them. Small, highly charged ions will form strong bonds while large, minimally charged ions will form weaker bonds.