2. The Heisenberg Uncertainty Principle states that it is impossible to know with high levels of certainty both the location and the velocity of an electron. The better you know where an electron is, the worse your knowledge of where it is going.
The solar system model of the atom uses orbits to show where the electrons are. Electrons do not really orbit the nucleus. They do live in regions of space called orbitals. Orbitals are organized by the energy level or shell that they belong to.
An orbital is the shape of the region in space where an electron is most likely to be found.

5. Schrodingers Cat!

6. Electron Cloud Model Mathematical construct
Electron density (probability)
Atomic orbital (region)

8. QUANTUM NUMBERS! “address” of an electron 4 numbers Principal – n
Angular momentum – l
Magnetic – ml
Electron spin - ms

11. S orbitals 1 s orbital for every energy level 1s 2s 3s
Spherical shaped
Each s orbital can hold 2 electrons
Called the 1s, 2s, 3s, etc.. orbitals

12. P orbitals Start at the second energy level
3 different directions (dumbbell shaped)
3 different shapes
Each orbital can hold 2 electrons

13. The p Sublevel has 3 p orbitals

14. The D sublevel contains 5 D orbitals
The D sublevel starts in the 3rd energy level
5 different shapes (orbitals) (four leaf clover)
Each orbital can hold 2 electrons

15. The F sublevel has 7 F orbitals
The F sublevel starts in the fourth energy level
The F sublevel has seven different shapes (orbitals), complex shape.
2 electrons per orbital

17. Summary
Starts at energy level

26. Pauli Exclusion Principal
“No two electrons in an atom can have the same set of quantum numbers n, l, ml, ms.”
Wolfgang Pauli (1925)

30. Homework!
Write one complete set of quantum numbers for all of the electrons in Argon-18.
What are the quantum numbers of the 13th electron?