Final answer:
Ice is less dense than liquid water due to the lattice structure formed by hydrogen bonding, which creates empty spaces between the molecules.
Step-by-step explanation:
The fact that ice is less dense than liquid water is not only due to hydrogen bonding, but also because of the way the water molecules are arranged. When water freezes, the molecules form a lattice structure where the hydrogen bonds force the molecules to line up in a way that creates empty space between them. This arrangement increases the overall volume of the solid, making ice less dense than liquid water.