1. Electron Configuration

2. Three rules are used to build the electron configuration:
Aufbau principle
Pauli Exclusion Principle
Hund’s Rule

3. Aufbau Principle
Electrons occupy orbitals of lower energy first.

4. Electron configuration
Orbital Filling Order (Diagonal Rule)

5. Aufbau Diagram

6. -Pauli Exclusion Principle (Wolfgang Pauli, Austria, 1900-1958) -Electron Spin Quantum Number
An orbital can hold only two electrons and they must have opposite spin.
Electron Spin Quantum Number (ms):
+1/2, -1/2

7. Hund’s Rule
In a set of orbitals, the electrons will fill the orbitals in a way that would give the maximum number of parallel spins (maximum number of unpaired electrons).
Analogy: Students could fill each seat of a school bus, one person at a time, before doubling up.

8. Aufbau Diagram for Hydrogen

9. Aufbau Diagram for Helium

10. Aufbau Diagram for Lithium

11. Aufbau Diagram for Beryllium

12. Aufbau Diagram for Boron

13. Aufbau Diagram for Carbon

14. Aufbau Diagram for Nitrogen

15. Aufbau Diagram for Fluorine

16. Standard Notation of Fluorine
Number of electrons
in the sub level 2,2,5
1s2 2s2 2p5
Main Energy Level Numbers 1, 2, 2
Sublevels

17. Shorthand Notation
Use the last noble gas that is located in the periodic table right before the element.
Write the symbol of the noble gas in brackets.
Write the remaining configuration after the brackets.
Ex: Fluorine: [He] 2s2 2p5

18. Aufbau Diagram

19. Electron configuration
Orbital Filling Order (Diagonal Rule)

20. Blocks in the Periodic Table

21. Electron Configuration Group Activity
Inquiry activity … meaning little help from Mr. D … I may guide you a bit
Something to do with building a model electron configurations???
Groups of 4
Faciliatator – Keeps group on task, makes sure that everyone is doing their job and helps out where needed, gets element card from Mr. D. Check with Mr. D. when you feel your group needs guidance.
Materials Manager- Gets materials from white box, you can only use these materials! If you want to use other materials, check with Mr. D.
Engineer – You will actually build the model that group suggests … you are the hands-on person.
Reporter – You will explain model to Mr. D. and answer any questions that he has. Other group members will be asked questions as well and need to be prepared.