Ice is an example of which solid type?

• A. Ionic Solids
• B. Covalent-network Solids
• C. Molecular Solids
• D. Metallic Solids

Answer: (C)

Ice is a molecular solid because its lattice is built from whole H2O molecules held together mainly by hydrogen bonds between molecules. Inside each molecule, the atoms are connected by strong covalent bonds, but the forces that link different molecules in the crystal are hydrogen bonds, which are much weaker than covalent bonds. This distinguishes it from ionic solids (lattices of ions) and covalent-network solids (a continuous network of covalent bonds across the structure), as well as from metallic solids (a lattice of ions with a sea of delocalized electrons). Ice’s properties—such as a relatively low solid-to-melt transition point and poor electrical conductivity in the solid—align with molecular solids.