Assume that water filling a crack in a rock undergoes cycles of freezing and melting. Which of the following statement is true?
A) Water shrinks as it freezes, causing the crack walls to be drawn closer together.
B) Water expands as it melts, causing the crack walls to be pushed apart.
C) Water expands as it freezes, causing the crack walls to be pushed apart.
D) Water shrinks as it melts, causing the crack walls to be pulled closer together.

Question

Quizplus · Accepted Answer

Water expands as it freezes, which means that when water in a crack freezes, it will exert pressure on the walls of the crack, causing them to be pushed apart. When the ice melts, the pressure is released, but the crack may remain slightly wider than it was before the ice formed. Over time, repeated cycles of freezing and melting can cause the crack to widen and deepen, which can eventually cause the rock to break apart.

Assume That Water Filling a Crack in a Rock Undergoes