Which of the following statements correctly describes the 1s bonding molecular orbital compared to the 1s antibonding molecular orbital?

• A. The 1s bonding orbital has higher energy and less electron density between the nuclei than the 1s antibonding orbital.
• B. The 1s bonding orbital has lower energy and greater electron density between the nuclei than the 1s antibonding orbital.
• C. The 1s antibonding orbital has lower energy and greater electron density between the nuclei than the 1s bonding orbital.
• D. The 1s bonding and 1s antibonding orbitals have the same energy and electron density distribution.

Answer: (B)

Verified step by step guidance

1. Understand that molecular orbitals are formed by the combination of atomic orbitals, and these combinations can be constructive or destructive.
2. Recognize that a bonding molecular orbital results from constructive interference of atomic orbitals, leading to increased electron density between the nuclei.
3. Know that increased electron density between nuclei in a bonding orbital leads to a lower energy state because the nuclei are held together more effectively.
4. Understand that an antibonding molecular orbital results from destructive interference, which creates a node (region of zero electron density) between the nuclei and thus higher energy.
5. Conclude that the 1s bonding molecular orbital has lower energy and greater electron density between the nuclei compared to the 1s antibonding molecular orbital.