Nitrogen is the gas that makes up the largest portion of Earth's atmosphere, accounting for about 78% by volume.
Quick summary
- Main component: nitrogen (N2) ≈ 78%
- Second most abundant: oxygen (O2) ≈ 21%
- Remaining ~1% includes argon, carbon dioxide, neon, helium, methane, krypton, hydrogen, and other trace gases, plus variable amounts of water vapor depending on location and conditions.
If you’d like, I can provide a simple breakdown of typical atmospheric composition by major components and explain how it varies with altitude or weather conditions.
