Classification of Crystalline Solids

Having split solids broadly into crystalline and amorphous, the unit now looks specifically at the four families of crystalline solid distinguished by the type of bonding holding their constituent particles together: ionic solids (electrostatic attraction between ions), covalent solids (a continuous three-dimensional network of covalent bonds), molecular solids (weak van der Waals or hydrogen-bonding forces between neutral molecules), and metallic solids (a lattice of metal cations embedded in a mobile sea of electrons). Each family's characteristic melting point, hardness and electrical behaviour f …