To determine which atom is most likely to accept electrons to form an ionic bond, we should look for an atom that has a strong tendency to gain electrons. In ionic bonding, nonmetals typically accept electrons, while metals tend to lose them.
-
A mercury ion with a negative 2 charge: This ion has already gained two electrons, so it will not readily accept more electrons.
-
A potassium ion with a negative 1 charge: Potassium typically loses an electron to form a positive ion (K⁺), and so it is not likely to accept electrons.
-
Radon, a noble gas with 8 valence electrons: Noble gases are generally very stable due to their complete valence electron shells and are not likely to accept electrons.
-
Sulfur, a nonmetal with 6 valence electrons: Sulfur has 6 valence electrons and needs 2 more to achieve a full octet (8 electrons). Hence, it has a strong tendency to gain 2 electrons and form an anion (S²⁻).
Based on this analysis, the atom that is most likely to accept electrons to form an ionic bond is sulfur, a nonmetal with 6 valence electrons.