Q. Which of the following linear combination of atomic orbitals will lead to formation of molecular orbitals in homonuclear diatomic molecules [internuclear axis in $z$-direction]? A. $2p_z$ and $2p_x$ B. $2s$ and $2p_x$ C. $3d_{xy}$ and $3d_{x^2-y^2}$ D. $2s$ and $2p_z$ E. $2p_z$ and $3d_{x^2-y^2}$ Choose the correct answer from the options given below:
A) A and B Only
B) D Only
C) E Only
D) C and D Only
Explanation
[Solution by Dr. Abubacker] Orbitals combine into molecular orbitals only if they have the same symmetry about the internuclear ($z$) axis. $2s$ and $2p_z$ both have cylindrical ($\sigma$) symmetry and overlap with a non-zero integral. $2p_z/2p_x$, $2s/2p_x$, $3d_{xy}/3d_{x^2-y^2}$ and $2p_z/3d_{x^2-y^2}$ have different symmetries and give zero net overlap. So only D. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.