CAN WATER ABSORB HEAT BETTER THAN MOST SUBSTANCES?

Water is a one-of-a-kind substance for many reasons. An obvious one is its unique ability to absorb heat. Water is able to absorb heat - without increasing much in temperature - better than many substances This is because for water to increase in temperature, water molecules must be made to move faster within the water; this requires breaking hydrogen bonds, and the breaking of hydrogen bonds absorbs heat.

Heat capacity is the capability of water to absorb heat without undergoing an increase in temperature. Water has a high heat capacity of ---. This means that even though heat energy is entering a body of water, that energy will not be reflected in the measured temperature of the water until more heat has been added.

Water is also able to retain heat better than many substances (i.e., resist cooling). This is because for water to decrease in temperature, water molecules must be made to move more slowly within the water; this requires the forming of hydrogen bonds, and the forming of hydrogen bonds gives off heat (hence counteracting cooling tendencies as heat is lost from liquid water). Note again the concept that if forming something requires energy, then breaking that now-formed thing probably releases energy, in this case as heat. Water's high specific heat serves to buffer the internal temperature of organisms, the temperatures of bodies of water, and the temperatures of the entire biosphere, all things that enhance the ability of life to survive on this planet.

You may ask yourself how this unique ability of water affects you. The answer is that high heat capacity plays a vital role in regulating global climate. A good example of this is that coastal regions typically have cooler climates than regions that are further in land. This is because the ocean water absorbs heat from the land, which has a lower heat capacity, and the temperatures increase at a slower rate. This effect of water is extended across the globe because 78% of Earth is made up of water.

In addition to a widespread effect on the planet, water's heat capacity helps animals regulate their internal temperatures, which must be sustained within a certain range. For aquatic organisms, the external environment is subject to fewer extreme temperature changes, so internal heat is easier to maintain constant.

Due to waters ability to absorb heat, water is valuable to industries and in your car's radiator as a coolant. The high specific heat index of water also helps regulate the rate at which air changes temperature, which is why the temperature change between seasons is gradual rather than sudden, especially near the oceans.