HL Only
2.2.15 Sigma & Pi Bonds
Head-on vs Sideways overlap.
Bond Overlap
Head-on overlap of two s-orbitals. Symmetrical around bond axis.
Orbital (Positive Phase)
Overlap Region
Sigma (σ) Bond
- Head-on overlap.
- Electron density between nuclei.
- Single bonds are sigma bonds.
Pi (π) Bond
- Sideways overlap of p-orbitals.
- Electron density above/below axis.
- Double bond = 1σ + 1π.