Which of the following molecules or ions contain polar bonds? (a) \(\mathrm{O}_{3}\) (b) \(\mathrm{S}_{8}\) (c) \(\mathrm{O}_{2}^{2-}\) (d) \(\mathrm{NO}_{3}^{-}\) (e) \(\mathrm{CO}_{2}\) (f) \(\mathrm{H}_{2} \mathrm{S}\) (g) \(\mathrm{BH}_{4}^{-}\)

A polar bond is a type of covalent bond between two atoms where the electrons forming the bond are unequally distributed. This causes a partial positive charge on one atom and a partial negative charge on the other atom. Elements with different electronegativities tend to form polar bonds.

Examine each molecule or ion to see if there is a significant difference in electronegativity between the bonded atoms. If there is, then those atoms form a polar bond.

Determine if each of the listed molecules or ions has polar bonds based on the difference in electronegativity:(a) \(\mathrm{O}_{3}\) - Contains polar bonds because oxygen atoms share electrons unequally.(b) \(\mathrm{S}_{8}\) - Does not contain polar bonds because the S-S bonds are between atoms of the same element, sharing electrons equally.(c) \(\mathrm{O}_{2}^{2-}\) - Does not contain polar bonds due to the same reason as S8.(d) \(\mathrm{NO}_{3}^{-}\) - Contains polar bonds between nitrogen and oxygen due to a difference in electronegativity.(e) \(\mathrm{CO}_{2}\) - Does not contain polar bonds as the molecule is linear and dipole moments cancel, but the C=O bond itself is polar.(f) \(\mathrm{H}_{2} \mathrm{S}\) - Contains polar bonds because of the difference in electronegativity between hydrogen and sulfur.(g) \(\mathrm{BH}_{4}^{-}\) - Contains polar bonds; boron and hydrogen have different electronegativities, and the B-H bonds are polar.