Structures and Bonding: Metallic Bonding

• Metallic bonding is the force that holds metal atoms together in a metal structure. • It involves the sharing of free electrons amongst a lattice of metal ions. • Metal atoms have outer electrons which can easily move away from the atoms. These electrons are delocalised, which means they are free to move throughout the metal lattice. • The positive metal ions are then attracted to these delocalised electrons, creating strong electrostatic forces of attraction. These are the metallic bonds. • Because of the delocalised electrons, metals are good conductors of electricity. The loose electrons can carry electrical charge through the metal. • Metals are also malleable and ductile, which means they can be bent and stretched into different shapes without breaking. This is because the layers of metal ions can slide over each other without breaking the metallic bonds. • The strength of a metallic bond depends on the number of electrons in the outer shell that become delocalised and the size of the ion. More delocalised electrons and smaller ions will result in a stronger bond. • Additionally, metals have high melting and boiling points due to the strong forces of attraction in metallic bonding which requires a large amount of energy to overcome. • Different metals have differing strengths of metallic bonding, leading to a range in boiling/melting points and varying hardness. For example, magnesium has a higher melting point than sodium due to stronger metallic bonding.