The ionic lattice

A regular arrangement of ions

The ions in a solid ionic compound are not randomly arranged. Instead, they have a regular, repeating arrangement called an ionic lattice. The lattice is formed because the ions attract each other and form a regular pattern with oppositely charged ions next to each other.

Sodium and chloride ions tightly packed in rows and columns.A two-dimensional model for the ionic lattice in sodium chloride

The lattice arrangement continues in three dimensions. This is why solid ionic compounds can form crystals with regular shapes. A crystal contains very many ions, so the ionic lattice is a ‘giant’ ionic lattice.

Ionic structure of sodium chloride forming a cubic latticeA three-dimensional model for the ionic lattice in sodium chloride

Ionic bonds

The ionic lattice is held together by ionic bonds. In three-dimensional models, ionic bonds are shown as straight lines between ions. This is only to keep things simple, because ionic bonds can act in any direction.

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Ionic bonds are strong electrostatic forces between oppositely charged ions

An explanation of ionic bonding