Why does ice float on top of liquid water?

• A. Because ice has a higher temperature than liquid water.
• B. Because ice molecules are heavier than water molecules.
• C. Because ice is less dense than liquid water.
• D. Because ice contains more dissolved gases than liquid water.

Answer: (C)

Verified step by step guidance

1. Understand the concept of density, which is defined as mass per unit volume, mathematically expressed as \(\text{density} = \frac{\text{mass}}{\text{volume}}\).
2. Recognize that whether a substance floats or sinks in a liquid depends on its density relative to the liquid; an object floats if it is less dense than the liquid.
3. Recall that water expands when it freezes due to the hydrogen bonding in ice forming a crystalline structure that occupies more volume than liquid water.
4. Since the mass of water remains constant but the volume increases upon freezing, the density of ice decreases compared to liquid water.
5. Conclude that because ice is less dense than liquid water, it floats on top rather than sinking.