Question

What Is Anomalous Expansion Of Water.

Answer 1

abnormal property of water where by it expands instead of contracting when the temperature goes from 4 degree celsius - 0 degree celsius. The density becomes less and less as it freezes because molecules of water normally form open crystals when in solid form. that is your answer. 

Answer 2

The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4oC to 0oC, and it becomes less dense.
Hope it helps!:)