1. Topic: Molecular Shape Do Now: Draw the Lewis Dot Diagram for N 2 and C 2 H 2

2. BONDING Capacity ELEMENT# of bonds it likes to make Halogen,F, Cl, Br, I1 Hydrogen1 O and S2 N and P3 C4

3. Molecular Shape H O H

4. Use the Lewis Structure Lewis structure is 2-D, but can help figure out 3-D shape

5. Molecular Shape Shape determined by two factors: 1. # of unpaired e - around the central atom 2. total # atoms bonded to central atom

6. It’s important to classify electron pairs as bonding or nonbonding Electron pairs repel each other: want to be as far apart from each other as can be Nonbonding pairs take up a little more room than bonding pairs

7. 2-Atom Molecules Atoms located right next to each other linear molecules!

8. 3-Atom Molecules linear or bent linear or bentLinear Bent

9. Lewis Structure of H 2 O = H:O:H.... H2OH2O 3 total atoms, free unpaired electrons = BENT

10. CO 2 Lewis structure: O :: C :: O........ 3 total atoms, no free unpaired electrons = Linear

11. 4 atom molecules They make triangles… …so we call them trigonal Planar or pyramidal

12. Trigonal Pyramidal = Free electrons around the central atom

13. 4-Atom Molecules: Trigonal Planar = no free electrons around the central atom

14. 4-Atom Molecules: Planar

15. 5-Atom Molecules: H : C : H H H.... Tetrahedral

16. Molecular Polarity Look at structure and shape of molecule - all bent molecules are polar Draw a If top/bottom and left/right are same then NONPOLAR If either of the two are different then POLAR

17. SymmetricalMolecules  Nonpolar – they don’t have poles

18. AsymmetricalMolecules  Polar – they have poles (different ends)

19. Let’s try a few… Name the SHAPE and POLARITY

20. BENT POLAR

21. Trigonal Planar POLAR

22. Tetrahedral POLAR

23. Trigonal Pyramidal POLAR

24. linear POLAR

25. linear POLAR

26. bent POLAR

27. tetrahedral NONPOLAR