A: When most liquids are cooled in a stable environment the same affects takes place on all of them: They shrink. This is not the case for the greatest biological solvent: water. When water is cooled is shrinks until a temperarture of 4 Degrees Celcius is reached then it begins to expand until it reaches the freezing point when it continues to expand more. This strange occurrence has to do with the fact that the structure of the water molecule is very unique.
Water is formed when a hydrogen atom bonds with two oxygen atoms. This bond gets stronger as the temperature decreases. The solid form of water which is ice is completely hydrogen bonded.