1. Chemical Bonding and Molecular Structure Chapter 12 Sec 12.8 - 12.10

2. Goals: 1.To use Lewis Structures as a way to predict the geometry of Molecules 2.Determine if molecules are polar or nonpolar

3. VSEPR Model Valence Shell Electron Pair Repulsion Model Bonds (pairs of electrons) attempt to move as far away as possible from one another in a molecule

4. This explains the Geometry of H 2 O Water is a “bent” molecule, because of the lone pairs around the central Oxygen atom

5. Various Geometry of Molecules See Examples on Next Slides (Hand-Out)

8. Polar or Non-polar Molecule? A molecule may have polar covalent bonds and not be polar overall ????????? Geometry must also be considered

9. Ammonia (NH 3 ) is polar 1.The bonds between hydrogen and nitrogen are polar covalent (∆EN =.87) 2.Pyramidal geometry of molecule points charges toward N

10. Carbon Dioxide is Non-polar Even though the bonds between carbon and oxygen are polar covalent (∆EN = 1.0), the pull of electrons is in equal and opposite directions because CO 2 is linear

11. Water is Wacky! Water has some strange properties due to its structure