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 gas that you canât see, taste, or smell, but it is in the air all around us. Everyone needs oxygen in order to live. The amount of oxygen in the air is always 21 percent. This is enough for people whose heart and lungs work normally. A person with heart or lung problems may benefit from breathing air with more oxygen.