Question

Assertion (A) The total energy of two molecular orbitals, however, remains the same as that of two original atomic orbitals.
Reason (R) The energy of the antibonding orbital is raised above the energy of the parent atomic orbitals that have combined and the energy of the bonding orbital has been lowered than the parent orbitals.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $A$ is incorrect; $R$ is correct.

Answer 1

Answer: (B)

According to assumptions of $MOT$, the atomic orbitals which undergo $LCAO$ must have the comparable energy because each specific orbital have its own specific energy depending upon various quantum number and their sum.
Thus, both $A$ and $R$ are correct, $R$ is not the correct explanation of $A$.