Which of the following cannot be regarded as molecular solid?
Crystalline solids are classified on the basis of intermolecular forces working in them with four categories – molecular, ionic, metallic and covalent solids. The constituent particles of molecular solids are molecules, further subdivided on the basis of the bond types.
According to the properties of these solids, only (iv) I2 is a molecular solid and the other options are covalent solids.
Thus, (i), (ii), (iii) are the solutions for this question.