Final answer:
The molecules in water are farther apart than in ice because they have more energy, which overcomes the hydrogen bonds and results in water being less dense than ice. Ice's lower density is due to the crystal lattice structure formed by hydrogen bonds during freezing.
Step-by-step explanation:
The molecules in water have more energy than the molecules in ice, which is why they are farther apart. This additional energy in the water molecules allows them to overcome the rigid hydrogen bond network that is present in ice, causing the water to have a lesser density than ice. It's important to note that this is an unusual property of water; most substances become denser when they transition from liquid to solid because their molecules have less kinetic energy and can pack more tightly together.
However, due to the orientation of hydrogen bonds in water as it freezes, the water molecules are pushed farther apart compared to their arrangements in liquid water. Therefore, ice has a unique crystal lattice structure that makes it less dense than liquid water, allowing it to float. This is crucial in natural environments, as it insulates bodies of water and protects aquatic life during cold temperatures.