Subtitle: Is the Atmosphere 70% Oxygen?
The composition of the atmosphere is incredibly complex, and the exact amount of oxygen in the air can vary depending on the region and altitude. Generally, the atmosphere is made up of 78% nitrogen, 21% oxygen, and 1% other gases. Of the 21% oxygen, only a small portion of that is actually usable by most living organisms.
Oxygen: Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, and is a highly reactive nonmetal and oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the third-most abundant element in the universe and the most abundant element by mass in the Earth's crust.
The exact amount of oxygen that can be found in the atmosphere can vary greatly between different regions and altitudes. At sea level, the amount of oxygen in the atmosphere is usually around 20.9%. However, in higher altitudes, it can range anywhere from 15 to 30%. Therefore, it is safe to say that the atmosphere is not 70% oxygen.
