Answer:
B-F bond is longest.
Explanation:
B-F has the longest bond length from B-N, fluorine is the highest electronegative element than the nitrogen and makes the bond stronger.
The bond length is determined by the bond or the number of bonded electrons. The higher the bond order, the stronger the pull between two atoms and shorten the bond length. Bond length is the sum of covalent radii of two atoms. Shorter the bond length harder to cleave.
