Which statement best explains why radon and krypton do not bond easily with other elements?

• A. They have completely filled valence electron shells, making them chemically inert.
• B. They are metals and tend to lose electrons easily.
• C. They have unstable nuclei that prevent chemical bonding.
• D. They have very high electronegativities, so they repel other atoms.

Answer: (A)

Verified step by step guidance

1. Identify the group to which radon and krypton belong in the periodic table. Both are noble gases located in Group 18.
2. Recall the general chemical property of noble gases: they have completely filled valence electron shells, which means their outermost electron shell is full.
3. Understand that a full valence shell makes atoms stable and less likely to gain, lose, or share electrons, which is necessary for forming chemical bonds.
4. Evaluate the given options by comparing them to the known properties of noble gases: they are not metals, their nuclei stability is unrelated to bonding behavior, and their electronegativities are not the main reason for their inertness.
5. Conclude that the best explanation is that radon and krypton have completely filled valence electron shells, making them chemically inert and unlikely to bond with other elements.