Which is denser, ice at 0 degrees c or water at 4 degrees c

a. the water
b. the ice
c. they both have the same density

Water at 4 degree celsius will have higher density.

Option A

Explanation:

Density is related to the ratio of mass and volume. When the water is cooled or heated, it expands. When it is cooled below 4 degrees, due to thermal expansion, the hydrogen bonds will be stronger and the water expands. When it expands there is an increase in the volume which makes the density to reduce.Hence in crystal formation, the density of water will reduce.