II). Metallic Bonding:
Metal atoms are held strongly to each other by metallic bonding. In the metal lattice, the atoms lose their valence electrons and become positively charged. The valence electrons no longer belong to any metal atom and are said to be ‘delocalised’. They move freely between the metal ions like a cloud of negative charge. Hence, this lattice structure is described as a lattice of positive ions surrounded by a ‘sea of mobile electrons’. Therefore a metallic bond can be defined as: ‘the force of attraction between positive metal ions and the sea of delocalised electrons.’
Physical Properties of Metals:
- They are good conductors of electricity.
- They are good conductors of heat.
- They are malleable (can be hammered into different shapes).
- They are ductile (can be drawn into wires without breaking).