during the winter months, water on the surface of a pond will typically freeze and this ice acts as an insulator for the water
beneath it. as a result, aquatic life is able to survive during the cold winter. the reason that this water expands upon freezing is
due to

Explanation:

Due to the crystalline arrangement of water molecules when it freezes, upon freezing the positive charge over hydrogen atoms in water attracts the water molecules and as the water starts freezing this attraction force form a crystal net in water with gaps in it. This crystal net structure take lot of space and hence water expands as it turns into ice.