Correct Option
Xenon (Xe) is referred to as the "Stranger Gas." Its name is derived from the Greek word "xenos," meaning strange or foreigner. This appellation reflects its rarity in Earth's atmosphere and its historical perception as an unreactive element. As a noble gas (Group 18), xenon possesses a complete outer electron shell, which contributes to its general inertness under normal conditions. Although once considered entirely unreactive, it has been observed to form compounds with highly electronegative elements, such as fluorine (e.g., XeF₂, XeF₄, XeOF₄), under specific and extreme experimental conditions.
Incorrect Options
Argon (A): Argon (Ar) is also a noble gas and is the third most abundant gas in Earth's dry atmosphere, after nitrogen and oxygen. While inert, it is not known as the "Stranger Gas."
Neon (B): Neon (Ne) is another noble gas, primarily recognized for its characteristic orange-red glow when used in discharge lamps, commonly known as neon lights. It is not referred to as the "Stranger Gas."
Nitrous oxide (D): Nitrous oxide (N₂O) is a chemical compound, not a noble gas. It is commonly known as "laughing gas" due to its euphoric effects and is used in medicine as an anesthetic and in various applications as an oxidizer or propellant. Its properties and nomenclature are unrelated to the term "Stranger Gas."