There are 6 types of electronic transitions that can occur in molecules: 1) σ→ σ* transition, 2) π → π* transition, 3) n→σ* transition, 4) n→π* transition, 5) σ→π* transition, and 6) π→σ* transition. These electronic transitions can be represented graphically using an energy level diagram.

2. Types of Transition
 The possible electronic transitions

3. Energy level diagram

4. The Possible Electronic Transitions Can
Graphically Shown As:

5. 1. σ→ σ* transition

6. 2. π → π* transition

7. 3. n→σ* transition

8. 4. n→π* transition

9. 5. σ→π* transition
6. π→σ* transition