Question

Assume internuclear axis to be z-axis, the correct molecular orbital representation of \(\pi^*\) antibonding molecular orbital formed by overlapping between two \(p\) orbitals will be: 

• A. Option 1
• B. Option 2
• C. Option 3
• D. Option 4

Answer 1

The Correct Option is C

Concept: \(\pi\) and \(\pi^*\) molecular orbitals are formed by sideways overlap of \(p\)-orbitals perpendicular to the internuclear axis. • \(\pi\) bonding MO: constructive overlap of lobes. • \(\pi^*\) antibonding MO: destructive overlap with a nodal plane between nuclei. If the internuclear axis is \(z\)-axis, then overlap occurs between \(p_x\) or \(p_y\) orbitals. 
Step 1: Nature of antibonding orbital In \(\pi^*\) antibonding MO: • Opposite phases overlap. • A node exists between the nuclei. • Electron density is outside the internuclear region. 
Step 2: Identify correct diagram Among the given options, diagram (3) correctly shows: • sidewise overlap • opposite phases of \(p\)-orbitals • nodal region between nuclei  Thus the correct representation is option (3). \[ \boxed{\text{Correct option: (3)}} \]