Which statement about noble gases is true?

Which statement about noble gases is true?

• A. They have full valence electron shells.
• B. They are highly reactive.
• C. They form many ionic compounds with chlorine.
• D. They are metals.

Answer: (A)

Noble gases are extremely stable because their outermost electron shell is complete. With a full valence shell, there’s no energetic drive to gain or lose electrons, so these atoms don’t readily form bonds. That completeness explains their lack of reactivity, their rarity in forming ionic compounds with chlorine, and why they are not metals. Some heavier noble gases can form very limited covalent compounds under special conditions, but the general, dominant property is the full valence shell that keeps them inert.

Noble gases are extremely stable because their outermost electron shell is complete. With a full valence shell, there’s no energetic drive to gain or lose electrons, so these atoms don’t readily form bonds. That completeness explains their lack of reactivity, their rarity in forming ionic compounds with chlorine, and why they are not metals. Some heavier noble gases can form very limited covalent compounds under special conditions, but the general, dominant property is the full valence shell that keeps them inert.