1. Molecular Shapes Molecules are three dimensional
Electron pairs repel each other
Molecular shape adjusts so that e pairs are as far apart as possible
Unshared electron pairs distort shapes further because they are more tightly held to one atom

2. Molecular Shapes Matter

3. What do covalently bonded molecules look like?

4. Is Shape Important?
Tasting sugars

5. C6H12O6
C6H12O6
C6H12O6

6. Glucose – 4 models

7. Glucose
Fructose
Lactose
Maltose
Sucrose

8. Steps to Determine Shapes

9. Valance Shell Electron Pair Repulsion Theory (VSEPR) or the get away from me Theory!

10. Remember the Lone Pairs!!

11. # of atoms around central atom # Total e pairs around central atom
Molecular Formula
# of atoms around central atom
Lone e pairs
# Total e pairs around central atom
Molecular Shape
CH4 4
Tetrahedral
NH3 3 1
Pyramidal
H2O 2
Bent

12. Steps to Determine Molecular Shape
Determine Total Number of valence electrons
Determine the central atom
Place e pairs between central atom and outside atoms
Place remaining electrons around outside atoms ( 2 or 8, depending)
The remaining electrons are placed around central atom
Determine number of e pairs around central atom
Determine number of lone pairs
Select correct shape from the table
Examine each central-peripheral bond for polarity
Decide on the overall molecular polarity

13. Remember the Lone Pears!!

14. Molecular Forces Intramolecular Forces Intermolecular Forces
Ionic
Bonds
Metallic
Bonds
Covalent
Bonds
Dispersion
Forces
Dipole
Forces
Hydrogen
Bonds