Question

Why is the melting point of a network solid so high? How is this related to what a network solid is?

Answer 1

A network solid is held together with numerous bonds in multiple directions, with the strong intermolecular forces effectively holding each atom in place. To melt the solid, those bonds must all be broken, which requires a large amount of thermal energy to be added to the network and accounts for the high melting point. Molecular solids, by contrast, have weak intermolecular forces and as a result relatively low melting points.