Bonding in ionic compounds

An ionic bond is an attraction between oppositely charged ions. After the ions are formed they all come together to form a lattice. A lattice is an infinite and repeating arrangement of particles. All the anions are surrounded by cations and all the cations are surrounded by anions.

The coordination number of an ion in an ionic solid is the number of oppositely charged ions which surround it. This varies from substance to substance but is usually 4, 6 or 8.