Q. Which of the following is paramagnetic ?
A) CO
B) O₂⁻
C) CN⁻
D) NO⁺
Explanation
[Solution from source] CO, CN⁻ and NO⁺ are isoelectronic with 14 electrons and have all electrons paired. O₂⁻ has 17 electrons, with one unpaired electron in a π* orbital, so it is paramagnetic. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.