Question

Ice floats on water because:

• A. its density is less than that of water
• B. crystal structure of ice has empty space
• C. both of the above
• D. none of the above

Hint:

Ice floats because hydrogen bonding creates an open structure → larger volume → lower density.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
According to Archimedes' principle, an object floats on a fluid if its density is less than the density of the fluid.
Step 2: Detailed Explanation:
1. Statement A: Ice has a density of approximately \( 0.9167 \text{ g/cm}^{3} \), while liquid water at \( 0^{\circ}\text{C} \) has a density of about \( 0.9998 \text{ g/cm}^{3} \). Since ice is less dense, it floats.
2. Statement B: The reason for this lower density is the crystal structure. In ice, water molecules form a tetrahedral network through hydrogen bonding, creating an open-cage structure with significant empty space.
Since Statement A is the physical reason for floating and Statement B is the structural cause for Statement A, both are correct descriptors of why ice floats.
Step 3: Final Answer:
Both the lower density and the open crystal structure contribute to the fact that ice floats on water.