The property that ice expands as it freezes demonstrates which characteristic of water?

• A. Ice has a lower density than liquid water.
• B. Water becomes heavier when frozen.
• C. Water expands when heated.
• D. Water becomes colorless only when frozen.

Answer: (A)

When water freezes, hydrogen bonds force the molecules into an open, lattice-like arrangement that takes up more space than in the liquid. This extra spacing makes ice less dense than liquid water, so the solid expands and can float on the liquid. That’s why ice expanding on freezing reveals this property: ice has a lower density than liquid water. The other statements don’t fit: mass doesn’t increase during freezing, expansion upon heating describes a different process, and colorlessness isn’t a feature unique to frozen water.