Electrical Conductivity
Delocalised electrons move freely and carry electric current. At higher temperatures, ion vibrations impede flow = higher resistance.
Malleability & Ductility
Layers of positive ions can slide past each other without breaking bonds because the electron sea holds them together.
Metallic Lustre
Delocalised electrons absorb photons and re-emit them, giving metals their characteristic shiny appearance.
High Melting Point
Strong electrostatic attraction between positive ions and the electron sea requires lots of energy to overcome.
At low temperature, ions vibrate slightly and electrons flow freely — metals conduct electricity well.