The air around us consists of
Nitrogen (Around 80%)
Oxygen is the second most common. (Around 20%)
Other gases present are much rarer
Argon (Around 1%)
Carbon Dioxide (Around 0.03%)
Also present at even lower levels are
Neon Helium Methane Krypton Hydrogen Xenon
These last few are very rare, from about 1 atom in every 50,000 molecules of air for Neon to around 85 to 90 in 1,000,000,000 for Xenon.
PS - I realise the figures add up to more than 100% but the figures are variable and so cannot be exact. PPS - It is also worth noting that these are the figures for the present time, the levels have fluctuated wildly when considered on a geological time scale.