Question

At 4 degree celsius temperature does ice float on water

Answer 1

Between 32 and 40 degrees Fahrenheit (0 and 4 degrees Celsius), the melted water actually contracts as the temperature rises. Beyond 40 F (4 C), it starts to expand again. This phenomenon makes ice less dense than the water around it, which is the reason why ice floats.

Answer 2

At 4 degrees C these two forces work out to make water the most dense. That is: the thermal properties are not enough to break all the h-bonds apart, but the h-bonds have not formed enough to widen the distance between water molecules to be as great as in ice (which is why ice is lighter than water).