Which of the following has the stronger bond?

Options

A. F-B
B. F-Cl
C. F-Br
D. Cl-Br

Answer

A

Explanation

`B(Z=5): 1s^2 2s^2 2p_x^1`
`F(Z=7): 1s^2 2s^2 2p_x^1 2p_y^2 2p_z^1`
F-B bond is the strongest. It is due to effective p-p overlap between half filled `2p_z` orbital of F atom and half filled `2p_x` orbital of B atom. p- Orbitals of almost equal size overlap more effectively.