| σ (sigma) bond | π (pi) bond |
| 1. It is formed when atomic orbitals overlap along internuclear axis. | 1. It is formed when atomic orbitals overlap side-ways (laterally). |
| 2. Electron density is high along the axis of the molecule (i.e., internuclear axis). | 2. Electron density is zero along the axis of the molecule (i.e., internuclear axis). |
| 3. In the formation of sigma bond, the extent of overlap is greater, hence, more energy is released. | 3. In the formation of pi bond, the extent of overlap is less, hence, less energy is released. |
| 4. It is a strong bond. | 4. It is a weak bond. |
| 5. Formation of sigma bonds involves s-s, s-p, p-p overlap and overlap between hybrid orbitals. | 5. Formation of pi bonds involves p-p or d-d overlap. The overlap between hybrid orbitals is not involved. |
