Ionic bonds form when a metal reacts with a non-metal. Metals form positive ions; non-metals form negative ions. Ionic bonds are the electrostatic forces of attraction between oppositely charged ions.
Positively charged Na ions and negatively charged Cl ions
The oppositely charged ions are arranged in a regular way to form giant ionic lattices. Ioniccompounds often form crystals as a result. The illustration shows part of a sodium chloride (NaCl) ionic lattice.
Properties of ionic compounds