ABSTRACT
It has often been stated that life depends on the ‘‘anomalous’’ properties of water. The high content of water in organisms contributes to its thermal regulation and prevents local temperature fluctuations. Water’s high latent heat of evaporation is responsible for increased resistance to dehydration and considerable evaporative cooling. Among the peculiarities of the water-phase diagram, the anomalous behavior of ice I is remarkable. Its specific volume is higher than that of the liquid phase, which, nevertheless, exists at temperatures higher than ice I. This effect results from the geometrical constraints of the ordered crystal structure of ice I, which occupies more volume than liquid water, where a dynamic (but strong) hydrogen bond system allows closer contact between molecules. This is a source of paradoxes, such as the floating of ice on water, which, incidentally, contributes to the essential role of water in the existence of life on Earth.
