HOW TO CONSTRUCT
A MODEL OF AN ATOM
Properly built with care this can be a very graphic and striking display.

 

Wire, Styrofoam Balls and Tubing for joiners are available at Tri-Ess Sciences.

For further information, please call  818-848-7838
Or FAX us at: 818-848-3521
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It is necessary for the student to understand the difference between building a model of an atom and building a model of a molecular structure.

ATOM: The smallest possible unit of an element. It consists of one or more protons and two or more neutrons (Hydrogen is the exception). These are located in the nucleus. The nucleus has from one to as many as seven orbiting rings surrounding it. Each of these rings contain electrons in varying amounts depending on the atom (element).

This is how an atom (element) is designated on the Periodic Chart.
 29                             63.54 
                              2.818.1

Cu
COPPER

9 = Atomic Number
63.54 = Atomic Weight
2.8.18.1 = Electrons in Ring
Cu = Symbol
Copper = Name

A model of an atom would look like this:

MOLECULE: A molecule consists of a combination of the same atoms or a combination of different atoms.

This is a written example of a combination of atoms:

             CH3CHO

This is a diagram of a combination of atoms:

     

This is a model of a combination of atoms:

                

Kits for the construction of molecules, known as Molecular Models are readily available.
However, kits for the assembly of an atom are difficult to obtain. Therefore, these 
instructions are to assist a student in assembly of their own model of the atom
of his choice.

Materials Needed:
Periodic Chart
 Wire, preferably music wire (1 piece 3/16" diameter by 36" long; and as many as 15 pieces of 3/64" x36" long)
2 colors of Quilters tacks
4"x4"x4" block of wood
1 4" Styrofoam Ball
Many 7/8" Styrofoam Balls
Joiners
Wrapping Wire
1 1" long piece of brass tubing
Glue, paint and basic tools.

Directions:

Drill a 3/16" hole in the center of the wood block.

Select the atom you wish to model from the Periodic Chart.
    The atomic number indicates the combined number of neutrons and protons in the nucleus.
    Divide this number in half.
    Using 2 colors of quilters tacks, pin this amount at random into the entire surface of the 4" Styrofoam Ball (nucleus).
    Insert the 3/16" x 36" wire through the nucleus and insert into the wood block.
    Position the nucleus in the center of the upright wire.

Referring to your Periodic Chart determine how many orbiting rings your atom will have. Using the thin wire, (3/64") form as many rings as you will need.
    The first ring will have a diameter of 8". The second ring will have a diameter of 10". Continue in 2" increments until you have the correct amount of rings.  If necessary, fasten two wires together to achieve the proper diameter.
   Before joining the wires, string the proper amount of electrons on each ring. (You may wish to paint the electrons before stringing). Join the wire ends by inserting into the 1" long brass tubing and crimp with a pair of pliers.
    Next fasten the rings to the upright around the nucleus. Begin with the 8" ring and fasten to the upright wire. Each succeeding ring should be at slight angles of each other. They should appear as the diagram below.

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