Molecular Forces

1. Estimate the order of separation of atoms in aluminium metal, given the density is 2700 kg m^-3, the molar mass of aluminium is 27 and the Avogadro constant is 6 x 10²³ mol^-1. [Answer: 2.6 x 10^-10 m]

2. Briefly explain (a) ionic bonds, (b) covalent bonds, (c) metallic bonds and (d) Van der Waal's bond.