Question

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

• they have many electron shells, so their protons do not attract electrons strongly.
• they have eight electrons in their valence shells, so they are stable without gaining or losing electrons.
• their valence shells are empty, so they do not need to bond with other elements to be more stable.
• their valence shells are so close to the protons in the nucleus that bonding cannot happen like in other elements.

Explanation:

Radon and krypton are noble gases. Noble gases have a full valence shell (8 electrons, except helium with 2), making them stable. They don't need to gain/lose electrons, so they don't bond easily. Let's analyze options:

• First option: Electron shells don't make protons attract electrons weakly; noble gases' stability is about valence electrons, not this. Eliminate.
• Second option: Correct. 8 valence electrons (octet) means stability, no need to bond.
• Third option: Valence shells aren't empty; they're full. Eliminate.
• Fourth option: Valence shell distance to nucleus isn't the reason; it's about full valence shells. Eliminate.

Answer:

They have eight electrons in their valence shells, so they are stable without gaining or losing electrons.