Which of the following solids is not a molecular solid?

Molecules are the constituent particles of molecular solids. These are further sub divided into the three categories: 1.Non polar Molecular Solids  2.Polar Molecular Solids: 3.Hydrogen Bonded Molecular Solids

HCl, H₂O(Ice), CCl₄ are examples of molecular solids.

Silicon dioxide is a covalent, three-dimensional network solid in which each silicon atom is covalently bonded in a tetrahedral manner to four oxygen atoms. Each oxygen atom in turn covalently bonded to another silicon atoms as shown in diagram .Each corner is shared with another tetrahedron. The entire crystal may be considered as giant molecule in which eight membered rings are formed with alternate silicon and oxygen atoms.