İlk 20 elementin elektron dizilimleri şu şekildedir: 1. Hidrojen (H): 1s^1. 2. Helyum (He): 1s^2. 3. Lityum (Li): 1s^2 2s^1. 4. Berilyum (Be): 1s^2 2s^2. 5. Bor (B): 1s^2 2s^2 2p^1. 6. Karbon (C): 1s^2 2s^2 2p^2. 7. Azot (N): 1s^2 2s^2 2p^3. 8. Oksijen (O): 1s^2 2s^2 2p^4. 9. Flor (F): 1s^2 2s^2 2p^5. 10. Neon (Ne): 1s^2 2s^2 2p^6. 11. Sodyum (Na): 1s^2 2s^2 2p^6 3s^1. 12. Magnezyum (Mg): 1s^2 2s^2 2p^6 3s^2. 13. Alüminyum (Al): 1s^2 2s^2 2p^6 3s^2 3p^1. 14. Silisyum (Si): 1s^2 2s^2 2p^6 3s^2 3p^2. 15. Fosfor (P): 1s^2 2s^2 2p^6 3s^2 3p^3. 16. Kükürt (S): 1s^2 2s^2 2p^6 3s^2 3p^4. 17. Klor (Cl): 1s^2