The total number of species from the following in which one unpaired electron is present, is \_\_\_\_. $\mathrm{N}_{2}, \mathrm{O}_{2}, \mathrm{C}_{2}^{-}, \mathrm{O}_{2}^{-}, \mathrm{O}_{2}^{2-}, \mathrm{H}_{2}^{+}, \mathrm{CN}^{-}, \mathrm{He}_{2}^{+}$

JEE Main · 2024 · 09 Apr 2024 · Shift 1 · Chemical Bonding and Molecular Structure

The total number of species from the following in which one unpaired electron is present, is ____.

N_{2}, O_{2}, C_{2}^{-}, O_{2}^{-}, O_{2}^{2 -}, H_{2}^{+}, CN^{-}, He_{2}^{+}

Answer: 4

One unpaired electron is present in

C_{2}^{-}

O_{2}^{-}

? — evaluating each by MO theory, the species with exactly one unpaired electron are

C_{2}^{-}

O_{2}^{-}

H_{2}^{+}

and

H e_{2}^{+}

— total 4. (

N_{2}

C N^{-}

O_{2}^{2 -}

are diamagnetic;

O_{2}

has two.)

JEE Main · 2024 · 09 Apr 2024 · Shift 1 · Integer answer