You can represent a molecule two-dimensionally, as a structural formula or
electron dot structure. Although such models are useful in certain contexts,
they do not accurately represent bond angles between atoms or shapes of
molecules. In this activity, you will construct three-dimensional models of
several molecules. You will use electron dot structures and structural
formulas to inform how you construct the three-dimensional models.
jelly beans, gum drops or gumballs; toothpicks; twist ties; colored pencils or
Identify the chemical and structural formulas and electron dot
structures of the following molecules:
Compare the information provided by a molecules chemical formula to
the information provided by its structural formula.
Fluorine is a toxic, reactive gas. Which representation (structural
formula, electron dot structure, or three-dimensional model) would
you use to explain why fluorine so reactive? Why?
Identify the bond types between the carbon and the two oxygen atoms
in the carbon dioxide molecule.
Explain why it is difficult to accurately represent ammonia two-
What is the major difference between the two-dimensional and three-
dimensional models of ethane and methane? When might you choose
to use a two-dimensional model rather than a three-dimensional model
when representing one of the molecules?