The most abundant naturally occurring gas is Nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%. The inert gas Argon (Ar) is the third most abundant gas at .
The most abundant naturally occurring gas is Nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%. The inert gas Argon (Ar) is the third most abundant gas at .