1. VSEPR Theory Valence Shell Electron Pair Repulsion
What does VSEPR stand for?
Valence
Shell
Electron
Pair
Repulsion
This means…electrons in the valence shell (lone pairs or bonding electrons) want to be as far away from each other as they can.
Remember, they have all of 3D space to work with!

2. 3-Dimensional Shape of Molecules
In a molecule with more than __two_atoms, the shape of the molecule is determined by the number of ___electron____ ____domains____ on the central atom. The central atom forms hybrid orbitals, each of which has a standard shape. Variations on the standard shape occur depending on the number of bonding pairs and lone pairs of electrons on the central atom.

3. Things to remember about Domains
A _domain___is a group of electrons, including both bonding pairs and lone pairs of electrons. In using the VSEPR model, we look at the DOMAINS around the central atom in a covalent compound.

4. Things to remember about Domains
Single, double and triple bonds are all DOMAINS. Double and triple bonds are treated in the __same__ way as single bonds in predicting overall geometry for a molecule, but multiple bonds have slight more repulsive strength and therefore will occupy a little more space than single bonds.

5. Things to remember about Domains
A lone pair of electrons is a DOMAIN as well. Lone electron pairs have a little more repulsive strength than the bonding pairs, so lone pairs will occupy a little more space than the bonding pairs.

6. Different Geometries
#1) If the central atom has __2__ electron domains, then its electron geometry is ___linear__. (and so is its molecular geometry)

7. Different Geometries
#2) If the central atom has _3__ electron domains, then its electron geometry is _trigonal planar___. (and it’s molecular geometry depends on lone pairs)

8. Different Geometries
#3) If the central atom has _4__ electron domains, then its electron geometry is __tetrahedral_______ (and its molecular geometry depends on lone pairs)

9. 3-Dimensional Shape of Molecules
Electrons repel one another, so when atoms come together to form a molecule, the molecule will assume the shape that keeps its different electron pairs as far apart as possible. When we predict the geometries of molecules using this idea, we are using the … Valence Shell Electron Pair Repulsion theory aka. VSEPR

10. Give it try!
Compare CH4, NH3, and H2O

15. Your Turn
Compare BF3 and O3 (remember when drawing O3, make sure all your electrons are accounted for, and give all atoms a full octet)