Question

many fish and aquatic plants can survive a cold winter because the layer of ice that forms at the top of the lake insulates the water below and prevents the lake from freezing solid. what unique property of water contributes to this effect? water expands and becomes less dense when it freezes. water forms hydrogen bonds with ions and other polar substances. water absorbs heat when it evaporates and forms a gas. water molecules completely separate into ions in solutions.

Explanation:

When water freezes, it expands and its density decreases. This causes ice to float on the surface of the water. The floating ice acts as an insulator, protecting the water below from freezing solid. This property is crucial for the survival of aquatic life in cold - weather conditions. The other options do not explain the insulating effect of the surface ice layer.

Answer:

Water expands and becomes less dense when it freezes.