Question

why does water expand on cooling?

Answer 1

Water is one of the few exceptions to this behavior. When liquid water is cooled, it contracts like one wouldexpect until a temperature of approximately 4 degrees Celsius isreached. After that, it expands slightly until it reaches the freezing point, and then when it freezes it expands by approximately 9%.

Answer 2

it is due to its anamolus expansion it expand in cooling from 4degree Celsius to 0 degree Celsius