7. Metallic bonding

• Metal elements exist as giant metallic particles structures. Outermost shell of electrons of metal atom is delocalised - electrons are free to move about metal. Leaves positive metal ion. E.g. Na+, Mg2+ . Positive metal ions are attracted to delocalised negative ions electrons. They form lattice of closely packed positive ions in sea of delocalised electrons- metallic bonding
• Melting point:

  Metals have high melting points because of the strong electrostatic attraction between positive metal ion s and delocalised sea of electrons. Number of delocalised electrons per atom affects melting point. More there are stronger bonding will be and higher the melting point. Mg2+ had 2 delocalised electrons per atom, so it got a higher melting point than Na+, which only has one.
• As there are no bonds holding specific ions together, metal ions can slide over each other when structure is pulled, so metal are malleable snd ductile
• Delocalised electrons can pass kinetic energy to each other, making metals good thermal conductors. Metals are good electrical conductors because delocalised electrons can move and carry charge
• Metals are insoluble, except in Liquid Metals, because of strength of metallic bonds