Final answer:
Among the options provided, the Al-P bond is the least polar due to the smallest difference in electronegativity between aluminum and phosphorus.
Step-by-step explanation:
The question asks which of the following bonds is the least polar: C-O, N-O, S-O, Al-P, or C-F. Polar bonds occur between atoms with a significant difference in electronegativity (EN), with the more electronegative atom gaining a partial negative charge.
The bond between Al (EN = 1.61) and P (EN = 2.19) is the least polar among the options listed. This is because the difference in electronegativity between Al and P (2.19 - 1.61 = 0.58) is the smallest compared to the differences in electronegativity for the other bonds listed.
In contrast, the C-F bond is definitely polar covalent since fluorine has a much higher electronegativity (EN = 3.98) than carbon (EN = 2.55), resulting in a significant EN difference (3.98 - 2.55 = 1.43), thus making it a very polar bond. Therefore, the Al-P bond is considered the least polar bond among the given choices.