Air Composition at Sea-Level

(in percent by volume at the temperature of 15°C and the pressure of 101325 Pa)

NameSymbolPercent by Volume
Nitrogen N2 78.084 %
OxygenO220.9476 %
ArgonAr0.934 %
Carbon DioxideCO20.0314 %
NeonNe0.001818 %
MethaneCH40.0002 %
HeliumHe0.000524 %
KryptonKr0.000114 %
HydrogenH20.00005 %
XenonXe0.0000087 %