Reference: Chemistry, 4^th ed, McMurray & Fay, Sections 7.4-12.

By building molecular models you will:

1. Explore the relationship between the central atom valence electrons and the electron cloud geometry.

2. Discover the relationship between the central atom valence electrons and molecular geometry.

3. Understand how both electron and molecular geometries impact the symmetry of the molecule and any resulting dipole moment.

4. Recognize how charge cloud geometry affects hybridization on the central atom.

5. Employ electronegativity to understand bond properties.

Before coming to laboratory on the attached chart fill in the columns for molecular formula and Lewis structure.

1. Arrange into groups of three or four (each side of a lab bench would make a good grouping).

2. Select a member to check out a model kit from the stockroom.

3. This person will be responsible for returning the kit with all its pieces to the stock room at the end of the laboratory.

4. The group will build a model for each of the above molecules and finish filling in the chart.

5. After the group is finished, each person will be quizzed orally and individually by the instructor on a selected molecule.

6. Show your chart to the instructor for grading.

7. Disassemble the molecules.

8. Place the pieces back in their assigned bags.

9. Return the kit to the stock room.

Model Kit Colors

Central Atoms

Beryllium or Iron Gray

Sulfur Yellow

Carbon Black
Oxygen Red

Fluorine Light Green

Phosphorous Light Brown

Chlorine Green

Xenon Purple

Bromine Brown

Copper Copper

Atoms-Ligands

Hydrogen White

Chlorine Green

Fluorine Light Green

Oxygen Red

Nitrogen Blue

Carbon Black

Bonds

Shared pair Gray

Lone pair Purple

Triple bond White

Electronegativity Table

 

Chart for Molecular Shapes