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.
Oxygen is a non-metallic element that constitutes for 21% of air. In humans, oxygen is primarily absorbed via the lungs and carried around the body in blood cells to provide the key element for cellular activity. The average level of oxygen in the blood is approximately 96% and if this oxygen consumption lowers over time, your health can be affected.