Q. Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them:
A) NO < O₂⁻ < C₂²⁻ < He₂⁺
B) O₂⁻ < NO < C₂²⁻ < He₂⁺
C) C₂²⁻ < He₂⁺ < O₂⁻ < NO
D) He₂⁺ < O₂⁻ < NO < C₂²⁻
Explanation
[Solution from source] Bond orders from MO theory: He₂⁺ = 0.5, O₂⁻ = 1.5, NO = 2.5 and C₂²⁻ = 3 (isoelectronic with N₂). So the increasing order is He₂⁺ < O₂⁻ < NO < C₂²⁻. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.