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Q.
If $Z$-axis is the molecular axis, then $\pi$-molecular orbitals are formed by the overlap of
Chemical Bonding and Molecular Structure
Solution:
If the $z$ axis is molecular axis, then $\pi$-molecular orbitals are formed by the overlap of $p_{x}+p_{x}$ It is formed by orbitals in the perpendicular plane to z -axis
So, the answer is $p x +p x$