Question

Classify each of the following solids as metallic, network covalent, ionic, or molecular.

(a) It is insoluble in water, melts above 500 °C, and does not conduct electricity either as a solid, dissolved in water, or molten.

(b) It dissolves in water but does not conduct electricity as an aqueous solution, as a solid, or when molten. 

(c) It dissolves in water, melts above 100 °C, and conducts electricity when present in an aqueous solution.