As pure water approaches its freezing point, the density decreases. Why does this happen?
A) The water compresses into ice.
B) The hydrogen bonds become rigid, allowing it to expand slightly.
C) The hydrogen bonds break as the molecules compress.
D) Ice takes up a smaller surface area than liquid water.

Question

Quizplus · Accepted Answer

When water molecules begin to freeze, the bond angles become wider. This allows the molecules to precisely come together in hexagonal patterns. This particular lattice pattern causes water to expand as it becomes a solid. The ice then becomes less dense than water. Information can be found in the section Water Has Unusual Thermal Characteristics.

As Pure Water Approaches Its Freezing Point, the Density Decreases