When two p orbitals are combined in molecular orbital theory, how many distinct linear combinations (molecular orbitals) can be formed?

• A. 1
• B. 2
• C. 3
• D. 4

Answer: (C)

Verified step by step guidance

1. Recall that when atomic orbitals combine in molecular orbital theory, the number of molecular orbitals formed equals the number of atomic orbitals combined.
2. Since we are combining two p orbitals, we start with 2 atomic orbitals.
3. Each pair of atomic orbitals can combine in different ways to form molecular orbitals: typically, one bonding orbital and one antibonding orbital.
4. However, p orbitals are directional and can combine in multiple orientations (e.g., along different axes), which can lead to more than just two molecular orbitals.
5. Specifically, two p orbitals can combine to form three distinct molecular orbitals: one sigma (σ) bonding, one sigma antibonding (σ*), and one pi (π) orbital, resulting in a total of 3 molecular orbitals.