JEE Advanced Chemistry Question (2023) — Solution

Step-by-step solution

The electronic configuration of fluorine atom is  1 s 2 2 s 2 2 p 5 . The fluorine molecule has 18  electrons. The s - p mixing occurs when the s  and p  orbitals have similar energies. The energy difference between 2 s   and   2 p orbitals in O ,   F ,   and   Ne is greater than that in Li ,   Be ,   B ,   C ,   and   N . Hence, the molecular orbital electronic configuration of  F 2  is  σ 1 s 2 σ * 1 s 2 σ 2 s 2 σ * 2 s 2 σ 2 p z 2 π 2 p x 2 = π 2 p y 2 π * 2 p x 2 = π * 2 p y 2 σ * 2 p z