Question

The chemical bond between which two atoms is most polar?

(1) C–N (3) S–Cl
(2) H–H (4) Si–O

Answer 1

(4) Si-O is the most polar, since their differences in electronegativity is the highest.

Answer 2

Correct Answer: option 4: Si-O

Reason:
The bond polarity depends on the electronegativity difference between constituent atoms. Greater the electronegativity difference, polar is the bond. In present case, electronegativity of Si and O is 1.9 and 3.44 respectively. Hence, electronegativity difference is 1.54, which is greater as compared to other bonds on present interest. Hence, Si-O bond is considered to be more polar.