Which of the following best explains why noble gases are generally nonreactive?

• A. They have very high electronegativity, preventing them from forming bonds.
• B. They have low atomic masses, so they do not interact with other elements.
• C. They have completely filled valence electron shells, making them chemically stable.
• D. They are all solids at room temperature, which prevents chemical reactions.

Answer: (C)

Verified step by step guidance

1. Understand that chemical reactivity is largely determined by the electron configuration of an element, especially the electrons in the outermost shell, called valence electrons.
2. Recall that noble gases are located in Group 18 of the periodic table and are known for their lack of chemical reactivity under normal conditions.
3. Recognize that noble gases have completely filled valence electron shells, meaning their outermost energy level is full of electrons, which makes them stable and unlikely to gain, lose, or share electrons.
4. Evaluate the other options: high electronegativity is not characteristic of noble gases; low atomic mass does not prevent chemical reactions; and noble gases are mostly gases at room temperature, not solids.
5. Conclude that the best explanation for the nonreactivity of noble gases is their completely filled valence electron shells, which confer chemical stability and reduce their tendency to form bonds.