What is the approximate percentage of oxygen in the air?
The air in Earth’s atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.
Oxygen is the most essential gas for the existence of biological life forms on Earth, even though it comprises only 21% of the air in our atmosphere. Oxygen is used for respiratory processes in animals to produce energy, for burning fuel to produce heat and light, as a coolant in high processing computers, and for providing a safe environment for newborns in pediatric incubators. Clearly, oxygen is a highly employed commodity in the world.