Choose a diatomic molecule (neutral or ion) from the dropdown in the control strip.
The left panel lists AO levels and valence electrons; the center column constructs the MO energy diagram based on the chosen scheme (early vs late second-row).
Electrons fill from lowest to highest energy following Hund’s rule; bonding orbitals are blue and antibonding are red.
The right panel reports bonding vs antibonding electrons, bond order (color-coded), magnetic character, and the corresponding Lewis bond symbol.
Compare molecules (e.g., O₂ vs O₂⁻ vs O₂⁺) to see how electron counts affect bond order and magnetism.
Classroom Ideas
Model Comparison: Show the difference between Lewis predictions and MO predictions for B₂ (Lewis says double bond, MO predicts single paramagnetic bond).
Ion Trend: Toggle O₂, O₂⁻, and O₂⁺ to discuss how adding/removing electrons alters bond order and magnetism.
Exit Ticket: Have students select CO or NO and write down the bond order and magnetic character with justification.
Educational Context
Subject: AP Chemistry — Molecular Orbital Theory
Grade Level: 11–12
Learning Objectives:
Construct qualitative MO diagrams for diatomic species.
Evaluate bond order and magnetic properties from the MO electron configuration.
Duration: 10 minutes (lecture demo or guided inquiry).
Prerequisites: Bonding, electron configurations, Pauli/Hund rules.
Assessment Idea: Provide a molecule from the list and ask students to explain why it is (para)magnetic using the MicroSim output.