1. Electron Configuration

3. What the Periodic Table would look like with the Lanthanides and Actinides inserted

6. Bohr Model

7. The Electron Cloud

15. AufBau Rule

16. AufBau Rule with Orbitals

17. Argon
Argon
18 Electrons
8 in Valence shell, therefore an inert (Nobel) element.

18. Potassium
Notice that we start a fourth shell before we fill up the third shell!
We would expect that shell 1 would hold 2, shell 2 would hold 8 and shell 3 would hold 18 but we start a fourth shell before we fill up the third shell.

19. Scandium
Notice that we start a fourth shell before we fill up the third shell!
We would expect that shell 1 would hold 2, shell 2 would hold 8 and shell 3 would hold 18 but we start a fourth shell before we fill up the third shell.

20. Periodic Table with Energy levels and Orbitals

21. Periodic Table with Elements, Energy Levels and Orbitals