Give an example of a substance that is MORE dense in its solid state when compared to its liquid state.

Wax

Explanation:

Density is defined as the mass contained per unit volume.

Usually solids are more denser than liquid, as molecules in solid are more strongly packed and thus have more mass per unit volume.

Liquids on the other hand contain molecules which are less tightly bound and thus thus contain less mass per unit volume as compared to solid.

Example: Solid wax is more denser than liquid wax.