Question

which atmospheric gas is being described? a noble gas (non - reactive), makes up approximately 1% of the atmosphere, third most common gas in air
oxygen
argon
methane
hydrogen

Explanation:

Oxygen is reactive and makes up about 21% of the atmosphere. Methane and hydrogen are reactive and present in trace amounts in the atmosphere. Argon is a noble gas, non - reactive, makes up approximately 1% of the atmosphere and is the third most common gas in air.

Answer:

B. argon