Explain how molecular orbitals are arranged for molecules with atomic numbers greater than 7 (e.g., O₂ and F₂). How does this differ from the molecular orbital arrangement in molec... Explain how molecular orbitals are arranged for molecules with atomic numbers greater than 7 (e.g., O₂ and F₂). How does this differ from the molecular orbital arrangement in molecules like N₂?
Understand the Problem
The question is asking for an explanation of the arrangement of molecular orbitals in diatomic molecules with atomic numbers greater than 7, specifically O₂ and F₂, and how this arrangement differs in diatomic molecules like N₂.
Answer
For O₂ and F₂, σ(2p_z) is lower than π(2p_x) and π(2p_y); this order is reversed in N₂ due to sp mixing.
Molecules with atomic numbers greater than 7 such as O₂ and F₂ have molecular orbitals where the σ(2p_z) orbital is lower in energy than the π(2p_x) and π(2p_y) orbitals. This differs from elements like N₂, where π(2p_x) and π(2p_y) are lower in energy than σ(2p_z) due to sp mixing.
Answer for screen readers
Molecules with atomic numbers greater than 7 such as O₂ and F₂ have molecular orbitals where the σ(2p_z) orbital is lower in energy than the π(2p_x) and π(2p_y) orbitals. This differs from elements like N₂, where π(2p_x) and π(2p_y) are lower in energy than σ(2p_z) due to sp mixing.
More Information
The difference in molecular orbital energy order between N₂ and molecules like O₂ and F₂ arises from reduced energy overlap and mixing between the 2s and 2p orbitals in O₂ and F₂.
Tips
A common mistake is to apply the same molecular orbital energy ordering across the entire second period without accounting for the differences in energies due to sp mixing.
Sources
- In molecular orbital theory, why do we follow a certain electronic ... - quora.com
- 9.5 Molecular Orbital Theory - Chad's Prep® - chadsprep.com
