Pure air, hypothetically speaking, consists exclusively of gases, primarily nitrogen and oxygen. In reality, truly "pure" air is difficult to find, as the atmosphere always contains trace amounts of other gases.
Here's a breakdown of the composition of air in Earth's atmosphere:
- Nitrogen (N₂): Approximately 78%
- Oxygen (O₂): Approximately 21%
- Other gases: The remaining 1% comprises gases like argon, carbon dioxide, neon, helium, hydrogen, and trace amounts of others.
It's important to note that the exact composition can vary slightly depending on location, altitude, and environmental conditions. The presence of pollutants can further alter the composition of air. Therefore, the definition of "pure air" is often theoretical, referring to air devoid of pollutants and solely composed of its natural gaseous constituents. According to NASA, air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.
