Classification of Crystalline Solids — Prelims Questions

Which of the following statements is INCORRECT regarding the classification of crystalline solids?

Which of the following substances is an example of a covalent network solid?

Which type of crystalline solid is characterized by having positive ions immersed in a 'sea' of delocalized electrons?

Arrange the following crystalline solids in increasing order of their melting points: $\text{I}_2$ (solid iodine), $\text{NaCl}$ (sodium chloride), $\text{SiC}$ (silicon carbide), $\text{Fe}$ (iron).

Which of the following properties is NOT characteristic of molecular solids?

Which of the following statements correctly describes the electrical conductivity of different crystalline solids?