4.5 Metallic bonding

Metals have low ionization energies, so valence electrons can be delocalized throughout metal.
Structure of metal is a giant lattice of positive ions (cations) surrounded by “sea” of delocalized electrons
Metallic Bond: the electrostatic attraction between a lattice of positive ions (cations) and delocalized electrons
Strength of metallic bond depends on
- Number of valence electrons that can become delocalized
- The charge of the metal ion
- The ionic radius of the metallic positive ion (cation)

Alloy is a mixture that consists either of
- Two or more metals
- Metal(s) combined with an alloying element (one or more non-metals)
Alloys have enhanced properties such as strength, hardness and durability

Metals are good conductors because the delocalized electrons can move through the metallic structure and carry a current
Presence of impurities can restrict movement

Metals are malleable because cations can slide past each other which leads to rearrangement of solid (Non-directional bonding)

Melting point depends on the strength of the attractive forces that hold the delocalized electron together