1. VSEPR

2. Homework:
-Turn it in

3. Objectives:
-I can reflect upon my assessment performance
-I can create a model of a Lewis Dot Structure
-I can prepare for the assessment

4. Where are we at? -Lack of Focus -Lack of Motivation -Lack of Review

5. Lots of responsibilities……..
-Chunking
-Dividing and conquering
-Personal accountability

6. This class is not,
-Biology
-Standard Chemistry
You will be held to a high expectation

7. Let’s Review
-Lewis Dot Structures
-Draw Assigned Lewis Dot Structure in the chart
-Then draw it on a whiteboard to share with the
Class
5 min to draw and solve it, then we will share

8. Recommendations:
-Take accountability for your learning
-Nightly review for min
-Come in with questions
-Hold yourself to your set standards

9. Additionally:
Step up and act like upperclassmen
Model the behavior you want others to have

10. Schedule Reset:
-Quiz Corrections, to earn up to 60%by Friday
-why wrong and what is the right answer
-Benchmark: Friday
-Assessment: Tuesday, Unit Test, Cumulative M/C and short answer

11. Reviewing the basics:
-Charge
-Valence Electrons
-Identifying an element
-Ionic vs covalent
-Ion VS polyatomic ion
-Where are transition metals?
-Dispersion is not the same as a metallic bond….
-Lewis Dot Steps

12. -Name the compound Pt₂O₃ SO₂ LiF

13. Valence Electrons: Model Covalent Compounds -Bonding Pair -Lone Pair

14. Basics of a Molecule Kit: -Holes -How to make a bond -Color System

15. Let’s Work through an example:
NCl₃
Lewis Dot
Build with a molecule kit
Draw as you see it when you
build it
Answer how many bonded
atoms and how many lone
pairs

16. Bond Pair VS
Lone Pair

17. Using the molecule kits
Make Lewis Dot
Build the compound Using
the molecule kit with a
Partner
3) Check your answers
4) Move on to the prior review
portion

18. Let’s Review: Each group will have one model to present to the class

19. Reflecting on your model…..

20. Where are the lone pairs on a molecule kit model? NCl3

21. Why are these molecules arranged in this pattern?

22. Lewis Dot Structures for: -CO2 -NH3 -H2O *COH2 -SO2 -CH4

23. Objectives
I can determine the molecular geometry and electron pair geometry of a compound

24. Yesterday…..

25. What is VSEPR Theory?

26. VSEPR: Valence Shell Electron Pair Repulsion
-Helps us to predict the geometry (shape of a molecule)
-Based on the lone pairs and the bonding pairs
Of electrons
-Electrons repel each other so an atom is organized and oriented to reduce this

27. Why is this important?
-Structure of molecules determines the chemical properties
-Identify the shape of a molecule and the properties to determine how it wil react

28. What do you need to know about molecular shape?
Steric Number
# of bonded atoms
# of lone pairs
Electron Pair Geometry
Bond Angle
Molecular Geometry
Structure
Example

29. What is a lone pair?
-Set of two electrons that are not in a chemical bond
-Lone pairs have a larger
Repulsive force

30. Steric Number:
-Number of units bonded to the central atom
-Lone Pairs
-Atoms bonded
-Example H20, oxygen is the central atom
-It has two sets of lone pairs
-It has two Oxygen bonded to it
Steric Number: 4

31. What is the steric number of CO2?

32. Electron Pair Geometry
-Molecular shape based on total number of things attached/bonded to central atom (does not distinguish lone pairs from bonded atoms)
Molecular Geometry
-Molecular shape with or without lone pairs
*When no lone pairs, MG and EPG are the same*

33. EPG and MG for Steric Number =2 *Linear

34. Bond Angle:
-How far apart each pair of electrons is
-ie how spread out are the different parts bonded to the central atom

35. Let’s Work through the Key Examples You Need to Know
Steric Number
# of bonded atoms
# of lone pairs
Electron Pair Geometry
Bond Angle
Molecular Geometry
Structure
Example 2 3 4

36. How do we determine the molecular structure?
Example: NH3
If only one thing is bonded to the central atom we will not determine any of the characteristics, only if SN is 2 or higher

37. Independent Practice:
-Work Through the Back page
-If needed, you may use the molecule kits
-Once completed pick up the review sheet

38. Questions?

39. Review Problems: -Complete the Review Worksheet for HW