Science.6
Constructing Elements
& Compounds
Essential Questions
1. What is the difference between elements and
compounds?
Vocabulary
element, compound, chemical
formula, chemical symbol,
atom, molecule, model
Name ______________________________
Date _______________________________
Objectives
1. Construct models of elements and compounds and
determine how many atoms of each element are in each
molecule.
2. Identify advantages and limitations to the model of the
atom.
All elements are made of one type of atom. Elements are represented by chemical symbols, and can have one
or many of the same type of atom. Compounds are formed when two or more elements combine to form a
different type of matter. Compounds are represented by chemical formulas, which show the numbers and
types of atoms that make up the compound. Today you will create elements and compounds out of modeling
clay, and distinguish which are elements and which are compounds.
Materials:
- modeling clay (red, yellow, blue)
- Toothpicks
- tray
Procedure:
1. Obtain enough clay to make four balls of each color. Each clay ball represents one atom of an element.
- Blue represents Hydrogen atoms
- Red represents Oxygen atoms
- Yellow represents Carbon atoms
2. Construct a model of each of the following elements and compounds listed below (a – d). If necessary,
use the toothpicks to connect your clay atoms. After you construct each model, fill in the blanks for
that element or compound in the Data and Observations section on the back of this page. After you
finish making each model, take them apart.
a. C (carbon): create one carbon atom
b. H2O (water): connect two hydrogen atoms to one oxygen atom.
c. H2 (hydrogen): connect two hydrogen atoms together
d. CO2 (carbon dioxide): connect two oxygen atoms to one carbon atom.
3. Once you have completed the table, put the colored clay back in its original pile, and collect the
toothpicks. Then answer the conclusion questions below.
Data and Observations
Chemical symbol or
formula
Number of atoms in element or compound
Hydrogen
Carbon
Oxygen
Element or
Compound?
Total
1. C (carbon)
2. H2O (water)
3. H2 (hydrogen)
4. CO2 (carbon dioxide)
Conclusion Questions:
1. Look at the table above. How did you know whether the example was an element or a compound?
2.
From the formulas given, identify each of the following as either an element or a compound:
Formula:
NaCl
Ag
Co
CO
SO2
H2
Element or Compound?
3. Nitrogen is in the air in the form of two nitrogen atoms fastened together, N2. Is nitrogen an element or is it a
compound? Explain.
4. How are the clay models similar to actual atoms? How are the clay models different from actual atoms?
5. What are the advantages of using clay models to represent atoms? What are the limitations to using clay
molecules to represent atoms?