1. Molecular Orbital Theory Atomic orbitals mix together and make: – Bonding Orbitals Electrons in these orbitals help hold atoms near each other – Antibonding Orbitals Electrons in these orbitals push atoms apart from each other – Nonbonding Orbitals Electrons in these orbitals have no effect on bonding Molecular Orbitals can: – be Sigma or Pi – be spread over multiple atoms

2. Molecular Orbital Theory Molecular Orbitals can: – be Sigma or Pi – be spread over multiple atoms

3. MO Diagram for H 2 H + H  H 2

4. Li 2 Bond Order: 2 electrons in a bonding orbital = 1 bond 2 electrons in an antibonding orbital = -1 bond

5. H 2 /He 2 Examples

6. What is the bond order of H 2 + 1.0 2.0.5 3.1 4.1.5 5.2

7. What is the bond order of H 2 - 1.0 2.0.5 3.1 4.1.5 5.2

8. What is the bond order of He 2 + 1.0 2.0.5 3.1 4.1.5 5.2

9. What is the bond order of He 2 1.0 2.0.5 3.1 4.1.5 5.2