Our experiment shows Dalton’s Law of partial pressures. The law states that the sum of different pressures equals the total pressure. This simply means that if air is 20% oxygen and 80% nitrogen at 100 kpa (this is regular air at sea level) 20 kpa comes from the oxygen and 80 kpa comes from nitrogen. This relates to scuba diving because of the levels of each gas at high depths.
As seen in the chart the nitrogen is at huge levels at deep depths. The larger the nitrogen levels, the better the chance of nitrogen narcosis, and the bends, under water sicknesses. This can be avoided for divers who dive deep by using nitrox. Nitrox is a special mix of air. Instead of the 20% oxygen and 80% nitrogen dive shops can make mixes of air that have 40% oxygen and 60% nitrogen. This will allow deeper depth without the nitrogen related sicknesses.
This chart shows the relation of nitrogen and oxygen in a 40% oxygen and 60% nitrogen mix. The nitrogen levels are much more reasonable around 132 ft- 198 ft. The reason pure oxygen is not used is because pure oxygen is toxic to humans. At deep depths oxygen starts to become huge in quantity, again, becoming toxic.