1. ValenceShellElectronPairRepulsion

2. What is VSEPR? VSEPR- Valence Shell Electron Pair Repulsion
Lewis Structures are 2D Shapes, where as VSEPR Molecules are 3D Shapes
VSEPR predicts the shape or “geometry” of the molecule
Lone pairs of electrons influence the shape by pushing other atoms as far apart from each other as possible
Constituent (definition): serving to compose or make up a thing; component (dictionary.com)

3. Key  Bonded electrons Lone pair electrons in the plane of the page
forward
backward
Lone pair electrons 

4. Linear X—A—X A—A Bond angle: 180°
2 constituents around the central atom
No lone pairs
Examples:
CO2
HCN F2
X—A—X or
A—A

5. Trigonal Planar A X Bond angle: 120°
3 constituents around the central atom
No lone pairs
Examples:
BF3 A X

6. Bent A X  Bond angle: < 120°
3 constituents around the central atom
1 lone pair
Examples:
SO2 O3 A X 

7. Tetrahedral A X Bond angle: 109.5°
4 constituents around the central atom
No lone pairs
Examples:
CH4 A X

8. Trigonal Pyramidal A X  Bond angle: < 109.5°
4 constituents around the central atom
1 lone pair
Examples:
NH3 A X 

9. Bent A X  Bond angle: << 109.5°
4 constituents around the central atom
2 lone pairs
Examples:
H2O
H2S  A X

10. VSEPR thought process Draw the Lewis structure.
How many constituents around the central atom?
What structure is this molecule based on (if all constituents were bonds)?
Any atoms replaced by lone electron pairs?
What is the final structure and angle?
Helpful video:

11. Example: PCl3 Lewis structure Number of constituents: 4
Base structure: tetrahedral
One lone pair of electrons
Final structure: trigonal pyramidal
bond angle: < 109.5° P Cl 

12. Angle size: smallest to biggest
Linear with 2 or 3 constituents: 180
Trigonal planar 3 constituents: 120 
Bent with 3 constituents: < 120 
Tetrahedral with 4 constituents: 
Trigonal Pyramidal with 4 constituents: < 109.5°
Bent with 4 constituents: << 109.5°