Modeling Molecules
Modeling Molecules
Introduction:
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.
Materials:
jelly beans, gum drops or gumballs; toothpicks; twist ties; colored pencils or crayons
Procedure:
1. Identify the chemical and structural formulas and electron dot structures of the following molecules:
water, ammonia, carbon dioxide, fluorine, methane, ethane
2. Write the formulas and draw the two-dimensional structures in the table.
3. Chose one color candy to represent each atom of an element (e.g., red jelly bean = hydrogen). Create a key that identifies each element.
4. Use the candy, toothpicks, and/or twist ties to construct a three- dimensional model of each of the aforementioned molecules.
5. Draw, as accurately as possible, each model in the table.
6. Answer the questions.
Table:
Molecule name
Chemical formula
Electron dot structure
Structural formula
Drawing of model
Water
H2O
H2O
Ammonia
NH3
NH3
Carbon dioxide
CO2
CO2
Fluorine
F
F
Methane
CH4
CH4
Ethane
C2H6
C2H6
Questions:
1. Compare the information provided by a molecules chemical formula to the information provided by its structural formula.
They are the same. I think? That’s what I found.
2. 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?
One reason
Introduction:
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.
Materials:
jelly beans, gum drops or gumballs; toothpicks; twist ties; colored pencils or crayons
Procedure:
1. Identify the chemical and structural formulas and electron dot structures of the following molecules:
water, ammonia, carbon dioxide, fluorine, methane, ethane
2. Write the formulas and draw the two-dimensional structures in the table.
3. Chose one color candy to represent each atom of an element (e.g., red jelly bean = hydrogen). Create a key that identifies each element.
4. Use the candy, toothpicks, and/or twist ties to construct a three- dimensional model of each of the aforementioned molecules.
5. Draw, as accurately as possible, each model in the table.
6. Answer the questions.
Table:
Molecule name
Chemical formula
Electron dot structure
Structural formula
Drawing of model
Water
H2O
H2O
Ammonia
NH3
NH3
Carbon dioxide
CO2
CO2
Fluorine
F
F
Methane
CH4
CH4
Ethane
C2H6
C2H6
Questions:
1. Compare the information provided by a molecules chemical formula to the information provided by its structural formula.
They are the same. I think? That’s what I found.
2. 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?
One reason