1. Quantum Mechanics

2. A photon checks into a hotel and the bell hop asks, “Can I help you with your luggage?” The photon replies, “I don’t have any . I’m traveling light.”

3. Electron Density
Based on Heisenberg uncertainty principle and Schrodinger wave equation
Gives the probability that an electron will be found in a particular region of an atom
Regions of high electron density represent a high probability of locating the electron
Representation of the electron density distribution surrounding the nucleus in the hydrogen atom; shows a high probability of finding the electron closer to the nucleus

4. Atomic Orbital
Way to distinguish Bohr’s model from the current quantum mechanical model
Probability of locating the electron in 3D space around the nucleus
Has a characteristic energy

5. Quantum numbers
used to describe atomic orbitals and to label electrons that reside in them
Principle quantum number (n)
Angular momentum quantum number
Magnetic quantum number
Electron spin quantum number

6. Principal Quantum Number n
distance of e- from the nucleus
n=1
n=2
n=3

7. Energy levels are like rungs of a ladder
Energy levels are like rungs of a ladder. You cannot be in between a rung
Energy levels in an atom’s electron are unequally spaced. The higher energy levels are closer together.

8. Angular Momentum Quantum Number
Shape of the “volume” of space that the e- occupies
s orbital
p orbital
d orbital
f orbital
smart people do fine

9. Magnetic Quantum Number
Describes the orientation of the orbitals in space
All orientations are identical in energy

10. s orbital
1 orientation
Sphere

11. p orbital
3 orientations
dumbbell

12. d orbital
5 orientations
Double dumbbell

13. f orbital
7 orientations
No name for this shape

14. Electron Spin Quantum Number
Electrons are thought to be spinning on their own axes-clockwise, or counterclockwise.
The up and down arrows denote the direction of the spin.

15. Summary Orbital shape # of orientations Total # of electrons s p d f 2
sphere 1
dumbbell 3 6
double dumbell 5 10
no name 7 14

17. Energy of Orbitals
depends on principle and angular momentum quantum numbers

18. Shielding Effect Why is the 2s orbital lower in energy than the 2p?
“shielding” reduces the electrostatic attraction
Energy difference also depends on orbital shape

19. Electron Configuration vs Orbital diagram
number of electrons
in the orbital
Electron configuration
for hydrogen-H
1s1
principal quantum
number n
Shape
Orbital diagram for hydrogen-H 1s 1s or

20. Aufbau Principle
“fill up” the lowest energy level first

21. Orbitals in the Periodic Table

22. Pauli Exclusion Principle
No two electrons can have the same 4 quantum numbers
Only two electrons may occupy the same atomic orbital, and these electrons must have opposite spins
Electrons that have opposite spins are said to be paired

23. Hund’s Rule
The most stable arrangement of electrons in an orbital is the one with the greatest number of parallel spins
e- will occupy singly before filling with opposite spins N

24. Practice
Fill in the condensed orbital diagram, and write the electron configuration for the following atoms s s s

25. Day 2-Exceptions to the rules and reading the table

26. Valence Electrons
Electrons in the outermost s and p orbitals (highest n shell)
These electrons participate in chemical reactions

27. Example of Exceptions to the Rules
Copper and chromium are exceptions to the Aufbau principle. These are not the only two exceptions.
Some configurations violate the Aufbau Principle because half-filled sublevels are not as stable as filled sublevels, but they are more stable than other configurations
Element
Should be
Actually is
Copper
1s22s22p63s23p63d44s2
1s22s22p63s23p63d54s1
Chromium
1s22s22p63s23p63d94s2
1s22s22p63s23p63d104s1

28. Reading the periodic table for electron configurations
Practice writing the electron configuration for the following elements:
1. Element # Element #26 3. Br 4. Y

29. Battleship fun WITH ELECTRON CONFIGURATIONS

30. Objective How to play battleship using the periodic table
Set up periodic table s, p, d, f-block to resemble “battleship gameboard”
GOAL: Memorize the sequence while having fun.
Let’s play!

31. Prior to playing
Students should be familiar with the concept of electron configuration
Ideal if they know the sequence but not necessary
Aufbau principle, Pauli Exclusion Principle, and Hund’s rule, and exceptions

32. The Real Deal
How is the “real” battleship game is played?

33. Setup of the Periodic Table
Label periodic table with white board markers
Model and explain rules of the game using labeled periodic table
5 ships:
1 ship= 5 elements (aircraft carrier)
1 ship= 4 elements (battleship)
2 ships =3 elements (destroyer)
1 ship= 2 elements (PT boat)
TOTAL: 5 ships

34. Playing the game Use paper score card
Use bottom game board as the record for what is being hit
Use the top of the game board to record your ships
Two day game: Part 1 (electron config) and Part 2 (noble gas config)
Monitor student progress

35. After the game Review how to READ the periodic table
complete PART 2 on the same sheet tomorrow
Revisit Aufbau principle, Pauli Exclusion Principle, and Hund’s rule, and exceptions

36. Noble Gas Configuration
Day 3

37. Noble Gas Configuration
What is the electron configuration for Ne?
Ne:
What is the electron configuration for Mg?
Mg:
What do both electron configurations have in common?

38. To figure out which noble gas to use find the noble gas that is closest to the element without going over in atomic number
Which noble gas is closest without going over? Rb Cl Ra

39. Write the noble gas electron configuration for the following atoms:
Practice
Write the noble gas electron configuration for the following atoms:
Na:
Mn:
Co:
Sn:

40. Heisenberg uncertainty principle (1927) states that it is impossible to know both the velocity and position of a particle at the same time.