When teaching static electricity, it’s tempting to tell kids the basics...
• like charges repel
• unlike charges attract
And to do this without actually allowing them to work through a process that develops this understanding. Teaching static electricity is compounded by the fact that much of what is happening is occurring at the atomic level… so we’re not going to be able to observe that directly.
How can we help kids develop a mental model of what’s going on?
Enter the manipulative worksheet.
To prep for this activity, I made movable electrons. I used flat, glass marbles you can find at the dollar store or floral section of a craft store. If you can’t find those, you could draw them onto transparent plastic cut into squares.
Kids need to have a picture of what’s going on at the atomic level. Students need to understand how electrons and protons behave in order to grasp the cause of attraction and repulsion they see in their experiments.
To begin, students show how all the atoms are neutral and the object has no charge. Stacking a negative electron on top of a positive proton makes a star which stands for a neutral atom.
After building the model they capture their work on a separate page of notes.
Are you familiar with Visual Instruction Plans (VIPs)? First pioneered by Fred Jones of Tools for Teaching, these plans help kids capture the sequence of a conceptual process. Often they’re used in teaching math, but I love them for teaching science concepts. VIPs help kids by using pictures to describe each. When finished they make great reference materials.
Next, they move some of the electrons from the cloth to the balloon. The latex of balloons tends to collect electrons and the cotton of the cloth tends to shed them. When electrons move you can see that both objects become charged… the balloon has a negative charge and the cloth a positive one. Students then draw this stage of the process.
Students assimilate concepts through exploration. Important ones here are:
like charges repel and unlike charges attract
electrons and protons have opposite charges
electrons can move from one object to another and this affects the charge on both objects
As teachers, we can try to shortcut the learning process by having kids learn and recite these expressions. Students become masters at repeating phrases we like to hear and we can conflate this with true understanding.
But comprehension takes time and attention. That’s why I do so much hands-on with my students—because it gives their hands something to do while their minds are processing!
Experience with charging balloons and PVC rods prepares students for abstract thinking. Understanding is built layer upon layer. Some students arrive at your class with some of these layers already in place. Others… not so much! But our job is to keep them busy while their brains are sorting out the various concepts and how they fit together.
Scientific understanding is comprised of a web that isn’t built in a day. Kids need time and activity to help construct it.
If you're interested in using this technique in your classroom, you can click here for a free lesson plan.
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