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Electric Zapper
Post-Lab Activity: Simplicity of Electricity
This activity is meant to extend your students’ knowledge of the topics covered in our Simplicity of Electricity lab.
Through this activity, your students will deepen their understanding of electric charges by creating an
“electrophorous” device, which will produce a spark that you can feel, hear, and see!
Grade Levels: 4-8
Estimated time: 30-40 minutes
Student Outcomes:
1. Students will be able to create a working “electrophorous” device to observe static electricity.
2. Students will be able to describe how electrons flow and behave in static electricity.
Next Generation Science Standards
Common Core ELA Standards
Physical Sciences Grade 4: 4-PS3-2;
Grades 4-5: Writing W.7; W.8
Grades 6-8: MS-PS2-5
Grade 4: Speaking and Listening 4.SL.1b-d
Disciplinary Core Ideas PS3.A Definition of Energy
Grade 5: Speaking and Listening 5.SL.1b-d
PS3.B Conservation of Energy and Energy Transfer
Grades 6-8: Writing W.7; Speaking and
PS2.B Types of Interactions
Listening SL.1b-e
California State Science Standards
Physical Sciences: Grade 4: 4.1.e, g; Grade 5: 5.1.c; Grade 8: 8.3.a
Investigation and Experimentation: Grade 4: 4.6.c, d; Grade 5: 5.6.c, h; Grade 6: 6.7.a, b, d; Grade 7: 7.7.a, d,
e; Grade 8: 8.9.a, b
Vocabulary:
Familiarity with these terms and concepts will enhance students’ experience in the activity.
• Conductor: a material that allows electricity to flow through it easily.
• Insulator: a material that does not allow electricity to flow through it easily
• Electrophorus: (from Greek, meaning “electricity bearer”) capacitive generator used to produce electrostatic
charge.
• Electricity: (from Greek, meaning “amber”) phenomena resulting from the presence and flow of electric charge;
includes: lightning, static electricity, electromagnetic field, and electromagnetic induction.
• Electron: subatomic particle possessing a negative (-) electric charge.
• Proton: subatomic particle possessing a positive (+) electric charge.
Materials:
• Piece of wool cloth or woolen sock
• Disposable aluminum pie pan
• Styrofoam cup
• Styrofoam plate
• Hot glue or tape
Procedure:
1. Students will work in pairs or groups of four for this activity. Each pair or group will receive one set of the materials
listed above.
2. Tape or hot-glue the open end of the Styrofoam cup to the middle of the inside of the aluminum pie pan.
3. Rub the bottom of the Styrofoam plate with the piece of wool for at least 1 full minute. Place the plate bottom side
up on a table.
• What’s going on? Rubbing the plate with the wool will give the plate a negative charge. The Styrofoam attracts the
electrons from the wool.
• Discussion:
w Why do we want the Styrofoam plate to be negatively charged?
Electric Zapper
Post-Lab Activity: Simplicity of Electricity
201 S. Market St.
San Jose CA. 95113
1-408-294-8324
thetech.org
w What will happen when we put the pie plate on top of the negatively charged Styrofoam plate? Why?
4. Pick up the pie plate by the cup and place it on the bottom of the Styrofoam plate.
• Discussion:
w Did anything happen? Why or why not?
5. With the pie plate still on the Styrofoam plate, touch the edge of the pie plate. (Students should feel a light shock
and may be able to hear it as well).
• Discussion:
w Did anything happen this time? What happened? Why do you think this happened?
• What’s going on? The pie plate had a neutral charge (even number of protons and electrons) when sitting on top
of the Styrofoam plate. The
negatively charged Styrofoam
plate repels the electrons that
are in the pie plate and
redistributes them away from
the Styrofoam plate. Now the
protons in the pie plate are
closest to the Styrofoam
plate. When you touch the
pie plate, the electrons in the
pie plate jump from the plate
to your hand.
• Discussion:
w Why did the Styrofoam plate repel the electrons in the pie plate? (Like charges repel one another; opposite
charges are attracted to one another).
w Why did the electrons on the pie plate jump from the plate to your hand? (Your body is a conductor)
w If the electrons jumped off of the pie plate, what kind of charge does the plate have now? What particles are
left on the plate? (The plate now only has protons and is positively charged. This process is called charging by
induction).
w This device is called an Electrophorus; which is a device that can carry an electrostatic charge.
Extended Learning
• Holding only the cup of your electrophorus device, touch the metal part of your device to other items to see if a
static shock is delivered. How many times can you touch the plate to other items or people before the charge
is neutral again? How will you recharge it? What items were touched with the electrophorus that made a
shock? Why did they make a shock? Students should create a chart depicting which classroom items allowed a
shock and which didn’t. These items should then be classified as conductors or insulators.
• Just after the electrophorus has just been charged, try turning out the lights and then touching the
electrophorus. Could you see the electrostatic shock? What did it look like? Why do you think it could be seen?
• Students should be able to draw a diagram, like the one above, showing how their electrophorus was charged
and the locations of the charges throughout the process.
Henderson, T. (1996-2001). The Physics Classroom. Retrieved January 2, 2014, from
http://www.mwit.ac.th/~physicslab/applet_04/physics_classroom/Class/estatics/u8l2b.html