1. Warm-Up: to be turned in Write the electron configuration, noble-gas configuration and orbital notation for: Sulfur and Calcium

2. VSPER Theory & Molecular Geometry

3. VSEPR Theory stands for “valence-shell, electron-pair repulsion” When bonding occurs, the electrons pairs will orient themselves so they are spread out as far as possible – Refers to valence electrons of central atom in the molecule

4. VSEPR Molecular Geometry Lewis Dot Structures can be used to predict molecular shape Actual shape of the molecule is determined by the atoms only – Unpaired electrons on the central atom do take up space, however, and do affect the shape – Total number of electron concentrations= Shared pairs + lone pairs Double and triple bonds are treated the same as single bonds, and have no affect on the molecular shape

5. Linear General formula: AB 2 2 atoms bonded to central atom Ex: CO 2 180° O C O

6. Trigonal Planar General formula: AB 3 3 atoms bonded to central atom Ex: BF 3 120° F B F

7. Bent 2 shared 0 lone Total: 3

8. Tetrahedral General formula: AB 4 4 atoms bonded to central atom Ex: CH 4 109.5° H H C H H

9. Trigonal Pyramidal General formula: AB 3 3 atoms bonded to central atom 1 lone pair of electrons on central atom Ex: NH 3 107° H N H H

10. Bent General formula: AB 2 E or AB 2 E 2 2 atoms bonded to central atom 1 or 2 Lone pairs of electrons on central atom Ex: H 2 O 105° O H H

11. Homework: Due 10/26/2012 Draw Lewis Dot Structures for the following molecules. Then predict the molecular shape according to VSEPR theory. SCl 2 PI 3 Cl 2 O NH 2 Cl SiCl 3 Br