What are the gases in Earth's atmosphere in order of most abundant to least?
The list below is as close as I could get it.
The following are in constant proportion, not varying from one location to another:
Trace elements include Ne, He and Kr at about 0.0001% each
Carbon dioxide 0.037%
Water vapour 0 to 4%, depending on location and season.
(The final four in "trace amounts" only.)