Concept:When water freezes, the molecules arrange themselves in a regular geometric pattern governed by hydrogen bonding.
Formula:Not applicable for conceptual questions.
Solution:- As temperature drops to \( 0^\circ\text{C} \), kinetic energy decreases, and hydrogen bonds lock the water molecules into a rigid, hexagonal lattice.
- This specific structural arrangement holds the molecules further apart than they are in the liquid state.
- These permanent "empty spaces" cause the total volume to increase by approximately 9%, resulting in lower density.
Why other options are incorrect:While intermolecular forces (specifically H-bonds) cause the arrangement, it is the resulting "empty spaces" that physically explain the increased volume. Ice does not contain ionic bonds or dominant Debye forces.
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