# Gas densities and the atmosphere [duplicate]

The density of nitrogen is greater than the density of oxygen, hence the denser nitrogen would be present in the lower atmosphere. If so it would be deprived of oxygen as it would be pushed to the higher atmosphere due to its low density. But we live due to the intake of oxygen from the lower atmosphere. How is this possible?

## marked as duplicate by Mithoron, Mathew Mahindaratne, Jon Custer, DrMoishe Pippik, TyberiusJul 25 at 14:42

• – Loong Sep 18 '16 at 20:11
• You have it backwards. Oxygen gas is more dense than nitrogen gas. – MaxW Sep 18 '16 at 20:44

Although you mixed up the densities of $\ce{N2}$ and $\ce{O2}$, $\ce{O2}$ being more dense than $\ce{N2}$ rather than the other way around, the meaning of you question is still clear and valid. To paraphrase: "Why aren't the Earth's gases separated based on density, such that the most dense lie at the bottom of the atmosphere and the less dense gases rise to the top?"