Q. Which of the following diatomic molecular species has only $\pi$ bonds according to Molecular Orbital Theory ?
A) $O_2$
B) $N_2$
C) $C_2$
D) $Be_2$
Explanation
[Solution] In $C_2$ ($\sigma_{1s}^2\sigma^*_{1s}{}^2\sigma_{2s}^2\sigma^*_{2s}{}^2\pi_{2p}^4$) the bond order of 2 comes from two $\pi$ bonds only. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.