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Understanding Static Electricity Mark as Favorite (4 Favorites)
LESSON PLAN in Observations, Electricity, Atoms, Model of the Atom, Subatomic Particles, Electron Transfer, Electrons, Electrons. Last updated July 23, 2024.
Summary
In this lesson, students will complete a series of activities to explore how the imbalance of charges in materials creates static electricity and how those materials interact with others around them. They will describe the relationship between atomic structure, specifically the role of protons and electrons, and static electricity.
Grade Level
Middle School, High School
NGSS Alignment
This lesson will help prepare your students to meet the performance expectations in the following standards:
- MS-PS1-1: Develop models to describe the atomic composition of simple molecules and extended structures.
- Scientific and Engineering Practices:
- Developing and Using Models
Objectives
By the end of this lesson, students should be able to:
- Recognize the basic properties of electric charge.
- Explain that the transfer of electrons between two objects causes static electricity.
Chemistry Topics
This lesson supports students’ understanding of:
- Subatomic particles
- Model of the atom
- Atomic structure
Time
Teacher Preparation: 20 minutes
Lesson: 50-60 minutes
Materials (per group)
- Two latex balloons, inflated
- Two strings cut into 30 cm in length
- Piece of wool
- Tape
- Piece of paper
- Small pieces of dry cereal (O-shaped)
- Mixture of salt and pepper in dish (coarse/large grain salt recommended)
- Empty soda can
Safety
- No specific safety precautions need to be observed for this activity.
Teacher Notes
- In the following activities, the students will discover that electrons can move from one object to another. When this occurs, one object will become positively charged and one item will become negatively charged. This opposite charge is how static electricity is created.
- This lesson was designed for a middle school audience but could also be used in an introductory high school chemistry course.
- Prior to completing this activity, students should know that matter can be subdivided into particles that are too small to see, as well as the charges and locations of the three subatomic particles (protons, neutrons, and electrons). One lesson that would be a good introduction before doing this lesson is Acting Out Atomic Structure, where students model the different parts of the atom.
- It could be helpful to begin the lesson by activating students’ prior knowledge of and experiences with static electricity by discussing the following questions:
- Have you ever been shocked after walking on a carpet or putting on a sweater? Combing your hair? Can you explain what caused the shock?
- Why do your clothes stick together when they come out of the dryer?
- Why do you sometimes get a shock on a cold day when you touch metal?
- What other experiences have you had with static electricity?
- The students will not necessarily know whether the balloon is gaining or losing electrons when it is rubbed with the wool, only that it is charged. Once they have identified that the balloons have opposite charges in the first analysis question of the first activity, you could tell them that the balloons gain electrons
and become negatively charged so that they can use this information to determine charges on other charged items throughout the lesson. Alternatively, you could not tell them and just have them talk about the charges in terms of “same charge as the balloon” or “opposite charge as the balloon,” but then they would have to guess at the charges to do the diagrams.
- As an extension, you could discuss the triboelectric series, which ranks common items/materials on how likely they are to gain or lose electrons. If you had this discussion before completing this activity, students could deduce for themselves that the balloons gain electrons from the wool to become negatively charged.
- If you tell students that the balloons have a negative charge once they are rubbed with the piece of wool, they may assume that the items that are attracted to the balloon are positively charged. At a lower level, you could accept that answer. In a more advanced class, you could point out to them that they don’t experience a shock when they touch those items, and the items aren’t attracted to or repelled by other objects generally, which indicates that they are not always charged. What they are seeing is instead an “induced,” or temporary charge caused by the nearness of a charged object (the balloon), which causes an uneven distribution of electrons in the object in question. For the example where a piece of paper is put between the two balloons, the extra electrons on the balloons “push” the electrons in the paper away from the part of the paper nearest the balloons, leaving that section of paper more positive. The neutral paper doesn’t have an overall charge, but since the electrons are unevenly distributed, there is an area that is positive and an area that is negative. A similar phenomenon happens with the cereal, pepper, and soda can. This is hinted at in pre-activity question #3 and should be discussed as a class before beginning this activity.
- The pepper and salt both experience induced charges as described above, but because the salt particles are heavier than the pepper particles, they will not be able to be held up by the attractive force exerted by the charged balloon as easily as the pepper. Some students might see both particles attracted to the balloon if they move the balloon too close/too quickly. This can be minimized by using larger, coarser grains of salt, such as sea salt or kosher salt.
- If you do not have tables in your room that students can tape the balloon/cereal strings to, you could instead tape them to meter sticks that students hold away from themselves. As long as the balloon/cereal are not touching/near anything else, the meter stick set up should work the same.
For the Student
Lesson
Background
An understanding of static electricity must begin with the concept that all matter is made of atoms, and all atoms are made of subatomic particles, among which are the charged particles known as protons and electrons. Protons carry a positive charge (+), and electrons carry a negative charge (-).
When two different materials come into close contact, for example, wool rubbing against a balloon, electrons may be transferred from one material to the other. When this happens, one material ends up with extra electrons and becomes negatively charged, while the other ends up with a shortage of electrons and becomes positively charged. These imbalanced charges on objects result in the phenomena we commonly refer to as static electricity.
Today, you will complete some activities related to static electricity to better understand the relationship between static electricity and the structure of atoms.
Pre-Activity Questions
- Which subatomic particles are transferred between objects to create static electricity? Why do you think this is the case? (Hint: Think about how the subatomic particles are arranged in an atom!)
- What happens if two negatively charged objects are brought together? Two positively charged objects? One negatively charged object and one positively charged object?
- If a negatively charged object is brought near a neutral object, what would happen to the charged subatomic particles in the neutral object? What would happen if you used a positively charged object instead?
- Using what you know about the structure of atoms and subatomic particles, make a claim as to how atomic structure is related to static electricity.
Problem
What does static electricity have to do with atomic structure?
Procedure
Activity 1: Exploration with Charged Balloons
Materials
- Two latex balloons, inflated
- Two strings, each about 30 cm in length
- Piece of wool
- Tape
- Piece of paper
Procedure
- Tie a piece of string around the knot of each of the inflated balloons.
- Attach one balloon by the string to the underside of your table with tape. Ensure that the hanging balloon is not touching anything.
- Rub wool on the hanging balloon to charge the balloon.
- Repeat step 3 with the second balloon.
- Bring this balloon close to the hanging balloon and write your observations in question 1 below.
- Draw a model of what is happening to the balloons in question 2 below.
- Put a piece of paper between the balloons and write your observations in question 3 below.
- Draw a model of what is happening to the balloons with the paper between them in question 4 below.
Analysis
- What happened when you moved the charged balloons closer together? What does this tell you about the charges on the balloons? Does this make sense based on how the balloons were charged?
- Draw a model of the balloons. (Include charges on your drawing – ask your teacher about the balloons’ charges - and arrows to represent the motion of the balloons.)
- What happened when the piece of paper was placed between the two balloons? What does this mean about the part of the paper that is nearest the balloons?
- Draw a model of the balloons with a piece of paper between them. (Include charges on your drawing and arrows to represent motion of the balloons.)
Activity 2: Swinging Cereal
Materials
- Balloon
- Piece of wool
- thread, small pieces of dry cereal (O-shapes)
- Piece of paper
Procedure
- Tie a piece of the cereal to one end of a 30 cm piece of thread. Attach the cereal to the underside of your lab table with tape Make sure the cereal does not hang close to anything else.
- Charge the balloon by rubbing it on a piece of wool.
- Slowly bring the balloon near the cereal and observe what happens.
- Draw a model of what is happening to the balloon and cereal in question 3 below.
- Now try to touch the balloon to the cereal observe what happens.
Analysis
- What happened when the balloon was placed near the cereal? Why does this happen?
- Draw a model of the balloon and the cereal. (Include charges on your drawing and arrows to represent the motion of the cereal.)
- What happened after the cereal touched the balloon? Why does this happen?
Activity 3: Separate Salt and Pepper
Materials
- Latex balloon, inflated
- Piece of wool
- Mixture of salt and pepper in dish
Procedure
- Charge the balloon by rubbing it on your hair several times or with the piece a wool
- Slowly bring the balloon close to the salt and pepper mixture (do not move too fast or get too close to the mixture, or both the salt and pepper will attach to the balloon).
- Pay close attention to which part of the mixture attaches to the balloon and which part remains on the dish.
- Draw a model of what is happening to the balloon and the salt and pepper mixture in question 2 below.
Analysis
- What happened when you moved the balloon close to the salt and pepper mixture?
- Draw a model of the balloon close to the salt and pepper. (Include charges on your drawing and arrows to represent the motion of the salt and pepper.)
Activity 4: Soda Can Roll
Materials
- Latex balloon, inflated
- Piece of wool
- Empty soda can
Procedure
- Place an empty soda can on the floor, lying on its side.
- Charge the balloon by rubbing it on your hair several times or with the piece of wool
- Hold the balloon about 2 cm away from the soda can.
- Move the balloon slowly away from the can and make observations.
- Draw a model of what is happening to the balloon and can in question 2 below.
- Using the balloon, see how fast you can make the can roll.
Analysis
- Describe what is causing the can to move.
- Draw a model of the soda can and balloon. (Include charges on your drawing and arrows to represent the motion of the can.)
Conclusion
Based on your observations, what can you conclude about the relationship between static electricity and atomic structure? Be sure to discuss the role of electrons and protons in static electricity. Write your conclusion in CER (Claim, Evidence, Reasoning) format – state your claim, include evidence to support your claim and provide your reasoning for how that evidence supports your claim.