Explanation
Argon is a noble gas because it belongs to Group 18 of the periodic table, characterized by a full valence electron shell, making it chemically inert. Hydrogen, oxygen, and nitrogen are reactive nonmetals, not noble gases.
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Argon is a noble gas because it belongs to Group 18 of the periodic table, characterized by a full valence electron shell, making it chemically inert. Hydrogen, oxygen, and nitrogen are reactive nonmetals, not noble gases.