Summary:
- When water freezes, it expands in volume as ice is formed.
- The density of any liquid increases as its temperature decreases.
- For most liquids, this continues as the liquid freezes and the solid state is denser than the liquid state.
- However, water behaves differently.
- It actually reaches its highest density at about 4°C.
- Ice is less dense than liquid water and so it floats.
- Since the ice does not sink, liquid water remains under the ice all winter long.
- This is important, as fish and other organisms are capable of surviving through winter.