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.
