Originally Posted by RED MX5,Oct 5 2007, 08:16 AM

Air:

Nitrogen N2 78.084%
Oxygen O2 20.947%
Argon Ar 0.934%
Carbon Dioxide CO2 0.033%
Neon Ne 18.2 parts per million
Helium He 5.2 parts per million
Krypton Kr 1.1 parts per million
Sulfur dioxide SO2 1.0 parts per million
Methane CH4 2.0 parts per million
Hydrogen H2 0.5 parts per million
Nitrous Oxide N2O 0.5 parts per million
Xenon Xe 0.09 parts per million
Ozone O3 0.07 parts per million
Nitrogen dioxide NO2 0.02 parts per million
Iodine I2 0.01 parts per million
Carbon monoxide CO trace
Ammonia NH3 trace