1. Valence Shell Electron Pair Repulsion (VSEPR) Theory
Valence shell electrons will arrange themselves about a central atom so that replusions among them are as small as possible
Used to determine the Molecular Geometry (Shape) of a molecule (Lewis Dot structures only give us the order of bonding)
Count the # of regions of high electron density: a region of high e- density is a bond (single, double or triple) or a lone pair.

2. CO2 Lewis Dot Structure VSEPR O=C=O
only tells us the bonding and not the Geometry
VSEPR
# of high e- density regions around the central atom
2 bonds and 0 lone pairs
Linear O=C=O OCO  180o
Therefore, the Molecular Geometry (Shape) is linear

3. BF3 Lewis Dot Structure VSEPR
# of high e- density regions around the central atom
3 bonds and 0 lone pairs
Trigonal Planar FBF  120o
 the Molecular Geometry (Shape) is Trigonal Planar

4. CH4 Lewis Dot Structure VSEPR
# of high e- density regions around the central atom
4 bonds and 0 lone pairs
Tetrahedral HCH  o
 the Molecular Geometry (Shape) is Tetrahedral C H

5. PF5 Lewis Dot Structure VSEPR
# of high e- density regions around the central atom
5 bonds and 0 lone pairs
Trigonal Bipyramidal FPF 90.0o & 120.0o & 180.0o
 the Molecular Geometry (Shape) is Trigonal Bipyramidal P F

6. SF6 Lewis Dot Structure VSEPR
# of high e- density regions around the central atom
6 bonds and 0 lone pairs
Octahedral FSF 90.0o & 180.0o
 the Molecular Geometry (Shape) is Octahedral F F F S F F F