Data and Observations
A. Complete the table below. Note that “CA” stands for central atom. Use the element’s symbol to represent the atom.
Formula
I2
OF2
NI3
SiCl4
BeCl2
BF3
Lewis Dot Diagram (Make
sure every atom has the
correct # of valence e-)
# of
Ligands
off CA
# of
Lone
Pairs of
e- off CA
Name of
Shape of
Molecule
3-D Structural Diagram (indicate
lone pairs)
Bond
Angle
Polar or
Non-polar
molecule?
Formula
SF6
CH2Cl2
PCl3
HCN
PF5
COCl2
Lewis Dot Diagram
# of
Ligands
off CA
# of
Lone
Pairs of
e- off CA
Name of
Shape of
Molecule
3-D Structural Diagram (indicate
lone pairs)
Bond
Angle
Polar or
Non-polar
molecule?
Name _______________
Chemistry
Period ___
Date ________________
Molecular Models LAB
Procedure
1. Obtain a molecular model building set. Study the color code identifying the different
kinds of atoms.
2. Observe that the following atoms have one hole (bonding site): hydrogen, halogens.
The atoms with two holes are oxygen and sulfur. A nitrogen atom has three holes,
and carbon and silicon have four holes.
3. Complete column 2, Lewis Dot Diagram, and then construct a model of each
molecule listed below.
4. Complete the data table.
Analysis and Conclusion
1. Which would repel other electron pairs more: bonding pairs or lone pairs of electrons? Why?
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2. Name two shapes that always produce polar molecules. Why is this so?
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3. What is meant by the terms “bonding pair of electrons” and “lone pair of electrons”?
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4. Why is it possible for a molecule to have polar bonds, yet be a non-polar molecule?
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5. Define resonance. Give two examples of molecules that show resonance.
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