Molecular orbitals arise from the linear combination of atomic orbitals. For diatomic molecules, this results in bonding and antibonding orbitals.
The wave functions of atomic orbitals from atoms A and B are denoted as \(\psi_A\) and \(\psi_B\), respectively.
Atomic orbitals combine constructively or destructively to form molecular orbitals:
Constructive combination yields a bonding molecular orbital, typically represented as \(\psi_A + \psi_B\).
Destructive combination yields an antibonding molecular orbital, denoted by \(\sigma^*\), and is typically represented as \(\psi_A - \psi_B\).
The antibonding molecular orbital, \(\sigma^*\), is formed through destructive interference of wave functions, creating a nodal plane between nuclei with low electron density.
Based on these principles, the accurate representation of \(\sigma^*\) is:
Correct Answer:\(\psi_A - \psi_B\)
Explanations for ruling out other options:
\(\psi_A - 2\psi_B\): This mathematical form is not a standard representation for molecular orbitals.
\(\psi_A + 2\psi_B\): This would intensify constructive interference and does not describe an antibonding orbital.
\(\psi_A + \psi_B\): This expression is characteristic of a bonding orbital, not an antibonding one.
