Chemistry I: Electron Configurations Worksheet
Reminders: Blocks indicate into which suborbitals the last/valence electrons go.

s block: Groups I & II A (alkali & alkaline earth metals)

p block: Groups III – VIII B (Boron – Helium /metalloids & nonmetals)

d block: Groups IIIA – IIB (Transition metals)

f block: Rare earth/ inner transition metals
Energy levels = period #s
The d block starts with the 3rd energy level even though it’s positioned in the 4th period’s row.
The f block starts with the 4th energy level even though it’s positioned in the 6th period’s row.
Electrons fill in the following order: 1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d,7p
Only 2 electrons can “fit” in any one suborbital: s has 2, p has 6 total, d has 10 total, & f has max of 14.
Both Cu & Cr are exceptions to the regular way of filling electron shells. See text.
Write electron configurations for the following. You may use [Kr] noble gas configuration for > #10.
1. He ___________________________________ 2. Ne ___________________________________
3. Al ___________________________________
4. Cl ___________________________________
5. K ___________________________________
6. Cr ___________________________________
7. Cu ___________________________________
8. Zn ___________________________________
9. Se ___________________________________ 10. Ag ___________________________________
11. Cd ___________________________________ 12. Te ___________________________________
13. Cs ___________________________________ 14. W ___________________________________
15. Fr ___________________________________ 16. F ___________________________________
17. Mg ___________________________________ 18. S ___________________________________
19. N ___________________________________
20. Br __________________________________
21. Ba ___________________________________ 22. C ___________________________________
23. Xe ___________________________________ 24. Ni ___________________________________
25. Pb ___________________________________ 26. Sn ___________________________________
27. Am ___________________________________ 28. U ___________________________________
29. Bi ___________________________________ 30. Au ___________________________________