Final answer:
Ice floats on liquid water due to its lower density, creating an insulating barrier that protects aquatic life in lakes and ponds during winter by keeping the water temperature beneath it stable enough to sustain life.
Step-by-step explanation:
The fact that ice floats in liquid water is due to its lower density than its liquid form. This is attributed to the rigid lattice-like structure formed by hydrogen bonds as water freezes. Because of its lower density, ice creates an insulating barrier on the surface of bodies of water like lakes and ponds, which protects the aquatic life beneath from freezing. This insulating layer allows ecosystems to survive harsh winter conditions by providing a stable environment where the temperature beneath the ice stays relatively constant, ensuring that liquid water and life can persist beneath the frozen surface.