argon vs inert gas

argon and inert gas both are nouns.

Word	Noun	Adjective	Verb	Adverb
argon	Yes	No	No	No
inert gas	Yes	No	No	No

As nouns, inert gas is a hypernym of argon; that is, inert gas is a word with a broader meaning than argon:

argon: a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
inert gas: any of the chemically inert gaseous elements of the helium group in the periodic table

Other hypernyms of argon include argonon, noble gas.

argon (noun)	inert gas (noun)
a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere	any of the chemically inert gaseous elements of the helium group in the periodic table