2.3.1—Metallic bonding

Metallic bonding is the electrostatic attraction between a lattice of positive metal ions and delocalized electrons.

Delocalized electrons can move through the structure and carry charge and thermal energy. Non-directional attraction allows layers of cations to slide while the bonding remains.

When a potential difference is applied, delocalized electrons drift through the fixed cation lattice and carry charge; the positive ions do not travel through the metal. When layers shift under force, non-directional attraction to the electron sea persists, explaining malleability rather than brittle fracture.

Property-to-use link: copper is used for electrical wiring because its delocalized electrons carry charge through the solid; aluminium can be rolled into foil because ion layers can shift while non-directional metallic attraction is maintained. A use must be justified by the relevant property, not merely by stating that the substance is a metal.