C. Discrete molecules linked by Van der waals forces
D. Lower melting point than molecular crystals
Explanation
Covalent network crystals, also known as giant covalent structures, are solids in which each atom is covalently bonded to its neighbors, forming a continuous network of chemical bonds.
Examples include diamond, graphite, and silicon carbide.
These materials have very high melting points due to the strong covalent bonds that hold them together.
