Final answer:
Decompression sickness, also known as 'the bends,' is caused by nitrogen gas forming bubbles in the blood due to nonpolar covalent nitrogen gas coming out of solution when a diver ascends too rapidly, reducing pressure too quickly. Water, with polar covalent bonds, is less efficient at dissolving nonpolar substances like nitrogen. Safe ascent practices, decompression stops, and treatment in decompression chambers are necessary to prevent and treat DCS.
Step-by-step explanation:
Decompression sickness (DCS), often referred to as "the bends," is a result of nitrogen gas bubbles forming in divers' blood and tissues due to rapid decreases in ambient pressure as they ascend too quickly from deep dives. This occurs because of changes in solubility related to pressure described by Henry's law.
a) Nitrogen gas (N2) is a diatomic molecule composed of two nitrogen atoms bonded by a nonpolar covalent bond. b) The solvent of blood is water (H2O), which is a molecule with a polar covalent bond between hydrogen and oxygen. c) When nonpolar gases like nitrogen mix with a polar solvent like water, they dissolve but not as efficiently as polar substances. Thus, under high pressures, an increased amount of nitrogen dissolves in the blood. Once the pressure is rapidly reduced, these nitrogen molecules come out of solution quickly, forming bubbles that can cause the symptoms of DCS.
To prevent DCS, divers are advised to ascend gradually to allow gases to dissolve out of the blood slowly, or to make several decompression stops to safely decompress. If prudent ascent rates are not followed, symptoms such as joint pain, rashes, and in severe cases, paralysis and death can occur. In such situations, treatment with hyperbaric oxygen in decompression chambers may be required.