Question

please answers me this question​

Answer 1

The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4°C to 0°C, and it becomes less dense. The density becomes less as it freezes because molecules of water normally form open crystal structures when in solid form.

Thus at 4℃ water has maximum density and minimum volume

The significance of this is that ice is less dense than water so it floats in water and thus the upper layer of water in lakes freze which provide as a thermal insulator and the below layer remains as water thus saving aquatic life