In this experiment we'll
create an object called a electrophorus. Using the materials listed above, we'll charge the
object and then discharge it creating a snap, a little electrical shock, and a bright
spark. If you're afraid of a little electrical shock then get Dad to discharge the
object for you. And for grins, don't tell Dad beforehand about the resulting spark
and shock. After all the amateur garage projects Dad has worked on, he's bound to be
used to electrical shocks by now...
- Use the pliers to remove the pen cartridge from the insides of the BIC pen. This
will be our 'handle'.
- Place the pie pan upside down on the table.
- Push a thumbtack down through the center of the pie pan.
- Turn the pan back over so you are looking at the inside of the pan. The point of
the thumbtack should be sticking up through the middle of the pan.
- Coat the thumbtack point with hot glue. Reeko's sure you figured out that the word
'hot glue' comes from the fact that the glue is HOT! So be careful.
- Push the bottom of pen body down onto the extending thumbtack point. You could
also use a pencil for this step and press the eraser end of the pencil down onto the
- Let the glue dry for a little while.
- Rub the styrofoam plate with the wool rag for about 45 seconds.
- Place a styrofoam plate upside down on the table.
- Using the pen 'handle' that we just created, place the pie pan on top of the upside down
styrofoam plate (the pen should be sticking up).
- Quickly touch the pie pan with your finger. It may produce a small shock.
- Remove the pie pan off of the styrofoam plate using the pen 'handle'.
- Discharge the 'charged' pie pan by touching it with your finger. If you feel
mildly unpleasant about the small electrical shock then use Dad as the discharge object.
Foreheads and ears make good targets - just make sure you have an escape route
Pretty cool, huh? You can recharge the pan by starting at step 8. After Dad
has seen (or felt) the results of this experiment, feel free to have a little fun and
chase him around the room with your newly built zapper.
So what have we learned here (besides the fact that Dad's can indeed glow in the dark)?
Rubbing the styrofoam plate with the wool rag creates a negative charge on the plate (that is, it attracts electrons from the wool). When you place the pie pan on top of
the styrofoam, the electrons on the styrofoam repel the electrons on the pan. The
pan at this point has a neutral charge. But when you touch the pan (while it is on
the styrofoam plate) the electrons travel off of the pan and onto your finger (possibly
creating a spark). Now the pan has a positive charge (it was charged by induction).
Now, by carrying this contraption by the insulated handle (the pen), you can carry a
positive charge all around the room. When you bring this positive charge near your
finger, or any other object that is a source of electrons, the positively charged pan will
attract electrons, creating a spark.
Parent's Note. Although an atom is normally electrically neutral, it
can lose or gain a few electrons in some chemical reactions or in a collision with an
electron or another atom. This gain or loss of electrons produces an electrically charged
atom called an ion. An atom that loses electrons becomes a positive ion, and an atom that
gains electrons becomes a negative ion. The gain or loss of electrons is called