Which law states that the amount of nitrogen a diver absorbs is directly proportional to the partial pressure of the gas?

The correct answer is Henry's Law, which describes the relationship between the solubility of a gas in a liquid and the partial pressure of that gas above the liquid. In the context of diving, when a diver descends, the partial pressure of nitrogen increases due to the surrounding water pressure. According to Henry's Law, the amount of nitrogen that can dissolve in the diver's tissues increases with this increased partial pressure. This principle is crucial for divers to understand as it helps predict nitrogen absorption, which is directly related to the risks of decompression sickness.

The other laws mentioned, while relevant in other contexts, do not specifically address the relationship of nitrogen absorption related to partial pressure. Boyle's Law pertains to the volume and pressure of gas, Dalton's Law relates to the total pressure of a mixture of gases and their individual partial pressures, and Charles's Law concerns the relationship between gas volume and temperature. None of these directly correlate with the solubility of gases in liquid as impacted by their partial pressures, making Henry's Law the appropriate choice for this question.