Final answer:
The K-I bond is the least polar among the given options because it has the smallest difference in electronegativity between the bonded atoms.
Step-by-step explanation:
To determine which bond is the least polar, we look at the difference in electronegativity between the two bonded atoms. The smaller the difference in electronegativity, the less polar the bond is. In the options provided:
- Fe and O form a polar bond due to a significant difference in electronegativity.
- K and I form an ionic bond, which typically involves a metal and a nonmetal with a considerable difference in electronegativity. However, both potassium (K) and iodine (I) have lower electronegativities compared to other elements.
- C and O form a polar bond because oxygen is significantly more electronegative than carbon.
- Mg and Cl also form an ionic bond as magnesium is a metal and chlorine is a nonmetal, with chlorine being highly electronegative.
Considering ionic character and electronegativity differences, K-I is the least polar, because it has the smallest difference in electronegativity amongst the given options. Therefore, the correct answer is K-I.