Which statement about noble gases is correct?

• A. They commonly form diatomic molecules
• B. They are typically monatomic and do not bond
• C. They are always solids
• D. They are liquid at room temperature

Answer: (B)

Noble gases have complete outer electron shells, which makes them exceptionally stable and chemically inert. Because their valence shell is full, they have little tendency to gain, lose, or share electrons, so they don’t form bonds with other atoms under normal conditions. That’s why they exist as individual atoms—monatomic—in the typical state of matter at room temperature. They aren’t commonly diatomic, they aren’t solids, and they aren’t liquids at room temperature. Only under extreme conditions can some form compounds or condense into liquids or solids at very low temperatures. This combination of stability and monatomic nature is why the statement describing them as typically monatomic and nonbonding is the best choice.