Why does ice float on water after it crystallizes?

• A. Ice contains trapped air bubbles that make it less dense than water.
• B. Ice has a lower density than liquid water due to its open hexagonal structure.
• C. Ice forms stronger hydrogen bonds, making it heavier than water.
• D. Ice is less polar than liquid water, causing it to float.

Answer: (B)

Verified step by step guidance

1. Understand the concept of density, which is mass per unit volume, and how it determines whether a substance floats or sinks in another.
2. Recognize that water molecules form hydrogen bonds, which influence the arrangement of molecules in both liquid water and ice.
3. Learn that when water freezes, it forms a crystalline structure with an open hexagonal pattern due to hydrogen bonding, which increases the volume occupied by the molecules.
4. Since the mass remains the same but the volume increases in ice, its density decreases compared to liquid water.
5. Conclude that because ice has a lower density than liquid water, it floats on top rather than sinking.