Metallic bonding

In a metal, atoms are arranged in a large, regular structure. Their outer-shell electrons are delocalised: they are not tied to any one atom and can move throughout the metal. The atoms become positive metal ions, arranged in a regular lattice surrounded by these mobile electrons.

The delocalised electrons can be pictured as a sea of electrons throughout the lattice. The positive ions attract the negatively charged electrons. This strong electrostatic attraction is called metallic bonding.

The attraction acts throughout the giant structure, holding the metal ions and delocalised electrons together. Metallic bonding is therefore strong and holds the metal together.