Which of the following molecules(s) show/s paramagnetic behavior? (A) \(\mathrm{O}_{2}\) (B) \(\mathrm{N}_{2}\) (C) \(\mathrm{F}_{2}\) (D) \(\mathrm{S}_{2}\) (E) \(\mathrm{Cl}_{2}\) Choose the correct answer from the options given below:

JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Chemical Bonding and Molecular Structure

Which of the following molecules(s) show/s paramagnetic behavior?
(A)

O_{2}

(B)

N_{2}

(C)

F_{2}

(D)

S_{2}

(E)

Cl_{2}

Choose the correct answer from the options given below:

Answer: (D)

Paramagnetism appears when a molecule carries one or more unpaired electrons. From molecular-orbital filling,

O_{2}

places its last two electrons singly in the degenerate

π^{*}

orbitals and so has two unpaired electrons, and

S_{2}

, lying directly below oxygen in the same group, has the identical

π^{*}

arrangement with two unpaired electrons. By contrast

N_{2}

F_{2}

and

Cl_{2}

have every electron paired. The species that show paramagnetic behaviour are therefore

O_{2}

and

S_{2}

JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Single correct option