Author: Joyce Brumberger
Through design and implementation of their own experiments, students will learn about static electricity and its relationship with various materials. Additionally, students will learn the conditions in which static electricity is produced and how it can be reduced.
What should students know as a result of this lesson?
- definition of the term static electricity
- conditions in which static electricity is increased
- conditions that will reduce static electricity
What should the students be able to do as a result of this lesson?
- identify how static electricity affects their daily lives
- design and implement an experiment
- write a procedure for an experiment
- collect and record data
- analyze data and draw conclusions from it
- 10" balloons - 1 per set of partners
- Sink with running water
- Rice puff cereal
- Paper towels
- Baskets or bins for materials
- Fluorescent light bulb
- Paper plates
- Van de Graaf generator (optional)
- Film canisters or other small container for lotions, creams, oils, other liquids
- Small spray bottles for water
Suggested list of materials below. Refer to the Triboelectric series chart to insure proper variety of materials. Collect objects made of:
- Polyester cloth
- Cotton cloth
- Aluminum - aluminum pans, cans
- Steel - perhaps leg of a chair
- Styrofoam - cups, packing peanuts
- Clear food wrap film (for example, Saran WrapTM)
- Tape (for example, ScotchTM)
- Polyethylene - Plastic grocery bags, dry cleaning bags
- Polystyrene - clear take-out food containers
- Polypropylene - #5 recycle plastic containers
- PVC - pipes, vinyl floor tiles
- Carpet remnants
- Ceramic tiles
- Lotions and creams (reduces static electricity)
- Oil - vegetable, mineral, baby (reduces)
- Febreze or other anti-cling spray product (reduces)
- Fabric softener liquid and/or sheets (reduces)
- Rub a balloon several times across your hair or that of a volunteer student.
- At a sink, run a thin stream of water from the tap. Bring the balloon near the stream of water. (The stream of water will bend toward the balloon.)
- Ask students to describe their observations and suggest explanations for why the water bent towards the balloon. Accept all reasonable explanations.
- Rub the balloon again and bring it toward one end of a fluorescent light bulb. (The bulb will begin to glow.)
- Ask students to describe their observations and suggest explanations for why the bulb began to glow. Accept all reasonable explanations.
Assessment: Assessment is ongoing as students orally present their observations and reasoning.
- Tell students to get a paper plate with the rice puff cereal and place it on their workspace. In lieu of rice puffs, small bits of paper can be used. Hole punches from the copy machine is an easy source for this.
- Tell them to rub the balloon again on their head several times and then bring it close to the rice puffs.
- Tell them to count the number of rice puffs that went on the balloon.
- Ask students to describe their observations and suggest explanations.
- Tell students to use the various materials provided and charge them by friction (rubbing them against another object). Tell them to explore which ones tend to attract the rice puffs and which ones, if any, do not. In each case, they are to rub the material several times and count the number of rice puffs that were attracted to the material.
- Ask students to describe their observations and suggest explanations.
- Ask students to rub the balloon and explore various substances that could be used to reduce the balloon's ability to pick up the rice puffs. Suggested substances are listed under the materials section.
- Continue to ask for descriptions of observations and suggested explanations.
Assessment: Assessment is ongoing as students orally present their observations and reasoning
1. What happens when a material is rubbed?
- Answers will vary, but many will say that the material becomes charged. All matter is made up of atoms. Inside the nucleus of the atom are protons and neutrons. The nucleus is very difficult to break apart. Electrons are negatively charged particles that orbit around the nucleus and can easily move from atom to atom. When two things are rubbed together, one of the materials becomes negatively charged because it attracts the electrons and gathers them up. The other material becomes positively charged because its electrons are pulled off of it.
2. Which materials tended to attract the rice puffs?
3. Which materials tended to reduce the balloons ability to attract the rice puffs?
- Answer will vary depending on the materials used. Lubricating materials such as oils, lotions, and water will tend to reduce static electricity. During the winter months, static electricity is more pronounced in northern climates due to the dry air inside a building as well as outside. In tropical climates, walking across a carpeted room and touching a door handle usually does not produce the transfer of static electricity in the summer or winter due to higher humidity. Warm air is capable of holding more moisture than cold air.
Assessment: Students' responses to key concepts and their responses to additional examples.
Static electricity can be useful, but in everyday living it usually is something to avoid.
- Tell students to compile a list of occasions when they have experienced static electricity in their everyday life. This may be done in small groups or as a whole group. Answers will vary, but examples may be walking across a carpeted floor and touching a door handle; brushing or combing one's hair; garments clinging to one's body; clothes clinging to each other after being removed from the dryer. Lightning and static on the radio are additional examples, but not ones in which experimentation can safely be conducted.
- Working in pairs, tell students to select two different circumstances and list three or more possible solutions to reduce static electricity. Explain that one solution must be different than anything they have tested to date. The professional development provider may choose to assign groups the circumstances to insure all the suggestions are explored or have representatives from each group choose from a hat that has all the circumstances discussed by the group on strips of paper.
- Instruct students to write a procedure for testing their solutions and provide a list of materials necessary to conduct an experiment. Accept all reasonable and safe solutions and materials.
- Instruct students to conduct their experiments and record findings.
Ask students to share and discuss their findings to the group at large.
Best Teaching Practices
- Learning Cycle
- Science Process Skills
Alignment with Standards
- MS-PS2-3 Ask questions about data to determine the factors that affect the strength of electric and magnetic forces.
- MS-PS2-5 Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact.
Common Core Standards:
- RST.6-8.3 Follow preciesly a multistep procedure when carrying our experiments, taking measurements, or performing technical tasks.
- WHST.6-8.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- WHST.6-8.9 Draw evidence from informational texts to support analysis, reflection, and research.
- Content Standard A: 5-8 Science as Inquiry
- Content Standard B: 5-8 Physical Scienc
- Content Standard G: 5-8 History and Nature of Science
- Grades 6-8 Physical Science Benchmark A
- Grades 6-8 Scientific Ways of Knowing Benchmark A
- Grades 6-8 Scientific Inquiry Benchmark A and B
All matter is made up of small particles called atoms. Atoms are the smallest units of an element that still contain the properties of the element. But atoms themselves are made up of many smaller particles. Three subatomic particles to be identified here are the protons and neutrons, located in the nucleus of the atom, and the electron, which whizzes all around the outside of the nucleus.
Protons carry a positive charge, electrons carry a negative charge, and neutrons have no charge. They are neutral. The protons and neutrons remain in the nucleus. The forces holding them there are so strong that it would take a nuclear reaction to alter them in anyway. The electrons however are outside the nucleus and can transfer from one atom to another. Some elements tend to lose electrons easily while others tend to gain electrons easily.
All atoms are neutral because they have an equal number of protons (positive charges) and electrons (negative charges). Therefore, when an atom loses electrons (gives away negative charges) it becomes positive. When an atom gains electrons (collects more negative charges) it becomes negative. When two objects are rubbed together, one object will lose electrons and the other one will gain electrons. The build up of electrons will remain until there is an opportunity for them to transfer from the built up stockpile to another location. While they are in the stockpile, they are considered static (not moving by transfer). Electricity is not completely understood, but at the simplest level electricity results from a flow of electron. Static electricity then is a stockpile of electrons that is unnoticed until it flows to another object.
The Triboelectric series chart identifies materials that tend to gain or lose electrons and those that tend to remain neutral. Moisture tends to reduce the flow of static electricity.
Paper towels with lotions and oils can safely be disposed of in the trash.
Goggles should be worn to protect eyes if balloons should break.
Static electricity is a common phenomenon, but most students have an ill-conceived notion of what it actually is. Static electricity has many useful applications such as in ink applied in a photocopy machine or paint sprayed at the auto manufacturing plant. Build up of static electricity on a grand scale can be dangerous and understanding how to reduce it in the home or in industry is important for all.
Ongoing throughout learning cycle.
Grouping Suggestions: Try to insure that all students have participated and expressed their ideas either verbally or through written comments. When working in pairs or groups try to make the groups as heterogeneous as possible being sensitive to specific needs of individuals.
Pacing/Suggested Time: Allow any individual who does not wish to participate in the transfer of static electricity from themselves to an object to work with an individual who will.
Static electricity experiments are best done on dry winter days.
Printable PDF Worksheets
The Triboelectric series chart that can be found at: http://www.school-for-champions.com/science/static_materials.htm