1. Pauli Exclusion, Hund’s Rule, Orbital Diagrams, Valence Electrons, Unpaired Electrons

2. Evaluation/ Assessment
Objective
Today I will be able to:
Explain the behavior of electrons based on Pauli’s exclusion Principle and Hund’s Rule
Illustrate the location of an electron by drawing an orbital diagram
Determine the number of unpaired electrons in an atom
Identify the location of valance electrons in an atom
Evaluation/ Assessment
Informal assessment – student responses when reviewing electron configuration problems, orbital diagrams and valence electrons. Listening to group interactions on practice sheets
Formal Assessment – collecting and analyzing responses to electron configuration worksheet 2 and the where is the electron lab. Reviewing responses to the exit ticket

3. Lesson Sequence Warm – Up
Explain: principles, rules and diagrams of electron configurations
Elaborate: Students complete orbital diagrams worksheet
Evaluate: Students will draw orbital diagrams on the board and explain their answers (informal assessment)
Explain: Valance Electrons Notes
Elaborate: Students complete a valance electrons worksheet
Evaluate: Students will share responses to the worksheet
Exit Ticket

4. Warm - Up Write the electron configuration for the following elements:
Magnesium
Iron
Arsenic
What is the abbreviated configuration for Sulfur?

5. Objectives Today I will be able to:
Explain the behavior of electrons based on Pauli’s exclusion Principle and Hund’s Rule
Illustrate the location of an electron by drawing an orbital diagram
Determine the number of unpaired electrons in an atom
Identify the location of valance electrons in an atom

6. Homework
STEM Fair Conclusion Due Tuesday

7. Agenda Warm – Up Collect Flame Test Lab
Notes Pauli Exclusion Principle, Hund’s Rule, Orbital Diagrams
Orbital Diagram Practice
Review Practice as a class
Valence Electron Notes
Valance Electron Practice
Exit Ticket
New Seats for B-day

8. Electron Configuration Rules and Principles

9. Aufbau Principle
Electrons fill in lower energy levels before filling in higher energy levels

10. Pauli Exclusion Principle
An orbital can hold a max of 2 e-
To occupy the same orbital, they must spin in opposite directions
If 2 e- occupy an orbital, they are said to be “paired”
If only 1 e- is present in an orbital, it is “unpaired”

11. Pauli Exclusion Principle

12. Hund’s Rule
e- occupy orbitals so that a max number of unpaired e- result
More stable arrangement

13. Orbital Diagram Shows the electrons in their sublevels
Represented with arrows

14. Orbital Diagram 1s 2s 2px 2py 2pz H ↑ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↑ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓He C ↑ ↓ ↑ ↓ ↑ ↑ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ Ne

15. Complete the Electron Configuration and Orbital Diagram Practice Worksheet

16. Review the Electron Configuration and Orbital Diagram Practice Worksheet

17. Valence Electron Notes

18. Valence Electrons Electrons in the outermost energy level
Determines the number of electrons an atom gains, loses, or shares
These are the electrons that are involved in bonding

19. Valence Electrons (skip)
Write the electron configuration for oxygen
1s2 2s2 2p4
Oxygen has six valence electrons (2s2 and 2p4)

20. Valence Electrons (skip)
Write the electron configuration for potassium
1s2 2s2 2p6 3s2 3p6 4s1
Potassium has 1 valence electron (4s1)

21. Valence Electrons
Exceptions are the d and f sublevels! Use the number of electrons in the last s sublevel (and the p sublevel, if available)
Write the electron configuration for Bromine
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
Bromine has seven valence electron (4s2 and 4p5)

22. Foreshadowing: Octet Rule
Most atoms want 8 electrons in their outermost level OR full s and/or p sublevels
Atoms will form bonds to achieve the desired amount of electrons
Atoms are most stable when they have a full outer shell

23. Complete Valence Electrons Worksheet

24. Review Valence Electrons Worksheet as a class

25. Exit Ticket For the element Chlorine: Write the electron configuration
Write the abbreviated electron configuration
Draw an orbital diagram
Explain why you drew the electrons in the location of the orbital's that you did
Determine the number of valence electrons

26. Exit Ticket Mol Monday # 1
How many molecules of CO are in 5.0 grams of CO?