7 most abundant elements/compounds in the atmosphere

1. Nitrogen (N2) 78.084%
2. Oxygen (O2) 20.9476%
3. Argon (Ar) 0.934%
4. Carbon Dioxide (CO2) 0.0314%
5. Neon (Ne) 0.001818%
6. Helium (He) 0.000524%
7. Methane (CH4) 0.0002%