1. Section 2: VSEPR Theory & Molecular Structure and Polarity
Note: Each student is to receive a molecular geometry handout

2. Valence Shell Electron Pair Repulsion Theory: VSEPR
The shape of a molecule may be predicted by the number of atoms and un-bonded electrons that surround an atom.

3. Linear:
Bond Angle: 180 degrees
Lone Pairs of Electrons = 0

4. Trigonal Planar
Bond Angle = 120 degrees
Lone Pairs of electrons = 0

5. Tetrahedral
Bond Angle = degrees
Lone Pairs of electrons = 0

6. Triganol bipyramidal Bond Angle = 90 degrees and 120 degrees
Lone Pairs of electrons = 0

7. Octahedral
Bond Angle = 90 degrees
Lone pairs of electrons = 0

8. square pyramidal

9. distorted tetrahedron

10. pyramidal

11. nonlinear

12. square planar

13. T-shaped

14. Bent

15. Bond Polarity: When molecules develop charged sides because one atom is pulling harder on the valence electron than the other.
Finding the bond polarity:
Step 1: Find the electronegativities of each atom.
Atoms with higher electronegativites pull harder on the electrons in bonding.
Step 2: Draw arrows to the atoms with the higher electronegativities.
Example: Water

16. Find the Lewis Dot Structure, polarity, and geometry for each:
NF ) CH3I
2) CO2

17. Activity: Find the Lewis Dot Structure, Geometric shape and Polarity.
H2O ) NCl3
3) SiO ) CF4
*5) SF *6) NH3

18. Extras
CCl4
AsBr3
XeF4

19. Geometry Quiz: Find the Lewis dot structure, geometry, and polarity (20pts)
NF3
SeH2
CH4
SiO2

20. Molecular Geometry Quiz (5 pts each): Draw the lewis dot structure, draw the polarities, & name the structure
CBr4
CS2
NHCl2