03.06B Molecular Models: Lab and Rubric
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In this assignment, you will draw models of four molecules based on their Lewis structures, and answer 5 questions about each molecule you draw.
Material Ideas
 multicolored gumdrops, marshmallows, other soft candy (to represent atoms in each model), fruit, aluminum foil, Styrofoam balls, cotton balls, play dough, cereal, balls, Q-tips, hair pins, balloons, molecular model kit, construction paper
 toothpicks (to represent the covalent bonds in each model), paperclips or stick like objects
 paper (to draw Lewis dot structures and/or pictures of the models)

Photo editing program , word processing program, digital imaging, presentation programs. See Web tools 2.0 or contact instructor for additional ideas.
Introduction
Chemists often use three-dimensional models to help represent the geometry, or shape of molecules. You can purchase a molecular modeling kit at university stores or on the Internet, but in this activity you can make your own kit using the items listed above.
In this assignment, you have several different options to depict or show the geometry of your molecule. One of the options was shown in the lesson.
Procedure
1. Build or draw the Lewis structure for each of the molecules listed below.
H
2
O, NH
3
, CH
4
, CO
2
2. Build or draw a model of each of the Lewis structures using any of the materials listed above (See lesson for an example). Here are the steps: a. For each molecule, represent each element with a spherical (ball shaped) object. b. Each single bond should be represented with a straight object, two straight objects should be used between two atoms to represent a double bond, and three straight objects should be used between two atoms represent a triple bond. c. Remember that the lone pairs on the central atom take up space and play a role in determining the shape of the molecule. Represent each lone pair (nonbonded pairs of valence electrons) on the central atom with a nonbonded object. The bonds and lone pairs on the central atom should be spread apart as much as possible. See example in lesson as a reference.
Conclusion
For each of your molecular models, include a Lewis structure drawing or picture of your model (1 pt for each molecular drawing). On your drawing or picture, include the following information:
1. What is the central atom? (1 pt for each molecule)
2. How many atoms are bonded to the central atom? (1 pt for each molecule)
3. How many lone pairs of electrons are on the central atom? (1 pt for each molecule)

4. How many single bonds are there in this molecule? (1 pt for each molecule)
5. How many multiple bonds (double and/or triple) are there in this molecule? (1 pt for each molecule)