Explain metallic bonding

Metallic bonding occurs due to electrostatic forces of attraction between a lattice of positively charged ions and a "sea" of delocalised electrons. (Draw diagram) These electrostatic forces are very strong, giving objects with metallic bonds high melting and boiling points because a lot of energy is required to overcome them. Objects with metallic bonds can conduct electricity because the free moving electrons in the "sea" can carry charge. This explains why metals can conduct electricity.