Question

Number of molecules/species from the following having one unpaired electron is ________.
\( \text{O}_2, \, \text{O}_2^{1-}, \, \text{NO}, \, \text{CN}^{1-}, \, \text{O}_2^{2-} \)

Answer 1

Correct Answer: 2

Based on Molecular Orbital Theory (M.O.T.):

For \( O_2 \):

Unpaired electrons: 2

For \( O_2^{1-} \):

Unpaired electrons: 1

For NO:

Unpaired electrons: 1

For \( CN^- \):

Unpaired electrons: 0

For \( O_2^{2-} \):

Unpaired electrons: 0

Consequently, 2 species exhibit precisely one unpaired electron (\( O_2^{1-} \) and NO).