1. Electron Configuration
Contemporary Chemistry
Mrs. Coyle

2. -Electron Configuration -Orbital Filling

3. Electron Configuration
The way electrons are arranged around the nucleus.

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

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

6. Pauli Exclusion Principle
An orbital can hold only two electrons and they must have opposite spin.

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.
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

16. B) -Standard and Shorthand Notation -Arrow Diagram

17. Aufbau Diagram for Fluorine

18. Standard Notation of Electron Configuration Example: Fluorine:
Number of electrons
in the sub level 2,2,5
1s2 2s2 2p5
Main Energy Level Numbers 1, 2, 2
Sublevels

19. 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

20. Arrow Diagram

21. Blocks in the Periodic Table