Crystalline solids are classified into four main classes. List them and provide an example for each.

• A. Ionic solid - Sugar
  Molecular solid - Silicone
  Metallic solid - Rubidium
  Covalent solid - Hydrocarbon
• B. Ionic solid - Rock salt
  Molecular solid - Argon
  Metallic solid - Gold
  Covalent solid - Graphite
• C. Ionic solid - Sugar
  Dispersion solid - Silicone
  Metallic solid - Rubidium
  Dipole solid - Ice
• D. Ionic solid - Rock Salt
  Dispersion solid - Dry ice
  Metallic solid - Bronze
  Dipole solid - Benzoic acid

Answer: (B)