1. Bell Ringer (on quarter sheet!)
Please have the following out on your desk:
Where are the following??
Alkaline Earth metal
- Labeled Periodic Table from yesterday
Element with 3 valence e-
- WS from yesterday (electron configuration)
Element that needs 2 e-
Total of 8 valence e-
-Periodic Table
Will form a +1 ion
Halogens
When completed, turn in to the box

2. New Terminology Berkner The Atom Energy Levels Sublevels Orbitals
Electrons
Hallways
Classrooms on each hall
Desks
You

3. S orbitals hold 2 e- P orbitals hold 6 e- D orbitals hold 10 e-
Dumb bell
Spherical
D orbitals hold 10 e-
F orbitals hold 14 e-
Eliptical

4. We will learn three ways to show electron configuration
Electron Configuration Notation
Orbital Notation
Lewis Dot Notation (1st 3 periods)

5. 1. Electron Configuration

6. Look at the electron configuration for Chromium:
1s2 2s2 2p6 3s2 3p6 4s2 3d4
Highlight the energy levels in yellow
Underline the sublevels in red
Circle the electrons in green

7. Look at the electron configuration for Chromium:
1s2 2s2 2p6 3s2 3p6 4s2 3d4
What does 3d4 mean?
4 electrons in
d shaped orbital
3 energy levels away from the
nucleus
How many valence electrons does chromium have?
2 electrons in outermost energy levels (4th energy level)

8. Electron Configuration Notation
Write coefficient for energy level.
Write letter for sublevel
Superscript (number on top) shows # of electrons at that level.
Na 1s22s22p63s1
C 1s22s22p2
It can also be expressed like this.
Nobel Gas Notation
[Ne] 3s1
[He] 2s2 2p2

9. The Order Electrons Fill Orbitals

10. Electron Configuration of Zr
1s2
2s2
2p6
3s2
3p6
4s2
3d10
4p6
5s2
4d2

11. Practice
Write the long hand configuration for the following elements.

12. Shorthand Notation

13. How do I write less? Na was 1s22s22p63s1
In shorthand, find the previous noble gas (one row up) Neon, put it in brackets, then continue with the next orbital (period#,s)
[Ne] replaces the 1s22s22p6
[Ne]3s1
C was 1s22s22p2 shortcut is [He]2s22p2

14. Core Notation of Sn
Locate Sn on the periodic table

15. Shorthand Electron Configuration of Sn
Sn [Kr]
The noble gas core is Kr

16. Sn [Kr]5s2 The noble gas core is Kr
From Kr, go 2 spaces across the s-block in the 5th row  5s2

17. Sn [Kr]5s24d105p2 The noble gas core is Kr
From Kr, go 2 spaces across the s-block in the 5th row  5s2
Then go 10 spaces across the d-block on the 5th row  4d10
Finally go 2 spaces into the p-block on the 5th row  5p2

18. 2. Orbital Notation Tells in more detail where the electrons are:
1. What energy level they are on
2. What sublevel they are on
3. What axis they are on (x,y,z)
4. What spin they have (clockwise/counterclockwise)

19. Aufbau Principle
Each electron occupies the lowest energy orbital available.
The “orbital diagram” is…
Page 135

20. The “d” orbitals fill up in levels 1 less than the period number, so the first d is 3d even though it’s in row 4.
S1 S2 1 2 3 4 5 6 7 p1 p2 p3 p4 p5 p6 3d 4d 5d

21. Aufbau Diagram – if you want to use this, memorize how to draw it
S levels hold 2 e-
P levels hold 6 e-
D levels hold 10 e-
F levels hold 14 e-
Look at the periodic table, and the blocks, how can you easily remember these numbers?

22. Hund’s Rule
If you have more than one orbital in a sublevel (p,d,f), place one electron in each orbital before you double up.

23. Pauli Exclusion Principle
Electrons have opposite spin directions
Maximum of two electrons may occupy a single atomic orbital

24. Orbital Notation Na ___ ___ ___ ___ ___ ___ 1s 2s 2p 2p 2p 3s
Letters/numbers represent energy level (remember start at bottom of chart)
___ lines represent 1 orbital each.

25. Practice
Show orbital notation for Cl and As Cl As

27. Practice Orbital Diagram!
Refer to a periodic table and write the electron configurations of these atoms. Write the orbital diagram for the orbitals not in the noble gas core. Zn I

28. Lewis Dot Structures

29. Lewis Dot Notation
Lewis Dot diagrams show electrons available for bonding (the outermost electrons, valence)
Valence electrons = the total electrons in the last principal quantum level (highest coefficient)

30. Reminders
Electron Configuration WS (picked up yesterday) will be due on Friday, 9/26
Skills check on electron configuration on Friday, 9/26
e- configuration Battleship tomorrow!

31. Exit Ticket
Write the electron configuration for Oxygen