Answer:
The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon as third.
Step-by-step explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The gases whose percentages do not change from day to day are nitrogen, oxygen and argon. Nitrogen accounts for 78% of the atmosphere, oxygen 21% and argon 0.9%. Usually, the 4 most abundant gases are:
Nitrogen (N2) - 78.084%
Oxygen (O2) - 20.9476%
Argon (Ar) - 0.934%
Carbon dioxide (CO2) 0.0314%