advanced practice nurse a registered nurse having education beyond the basic nursing education and certified by a nationally recognized professional organization in a nursing specialty, or meeting other criteria established by a Board of Nursing.
Quick Answer. The air that makes up Earth's atmosphere contains 20.9 percent oxygen. This is true up to about 70,000 feet above sea level. However, above 10,000 feet, the atmosphere becomes too thin to support human life, even though its proportions do not change much. Continue Reading.
A full E-cylinder (the most common size for medical point-of-care use) of oxygen is at a pressure of roughly 2200 psi, equivalent to about 150 atmospheres. The cylinder typically contains 680 liters. If diluted to 21% by adding nitrogen to make normal room air, the oxygen in the cylinder would thus be equivalent to 680/0.21 = 3,238 liters of air, or 114 cubic feet of air at one atmosphere. [ answer edited to correct errors per Vivienne Marcusâs comment.]