Students observe phenomena in which A balloon sticks to the wall after being rubbed on hair A plastic bottle picks up small pieces of paper after being rubbed on cloths Etc 1 The formatting and presentation for this sticky tape experiment is from the NGSS Rollout 3 ID: 551877
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Slide1
Why do some things attract each other and other don’t?
Students observe phenomena in which:A balloon sticks to the wall after being rubbed on hair;(A plastic bottle picks up small pieces of paper after being rubbed on cloths;Etc …)
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The formatting and presentation for this sticky tape experiment is from the NGSS Rollout 3Lesson written by Maria Simani and Laura Henriques
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Why do some things attract each other and other don’t?
Scotch tape investigations: Observe how objects become charged; Identify patterns of how charged objects interact with each other;Begin to develop a model to explain these observations.3Slide4
Getting a Charge Out of Tape
Each person in your group will use two 1-2” pieces of tape to become electrically charged by following the steps below.4
1. Fold over one end of the tape to make a non-stick handle.
2. Stick this piece of tape to the table (or back of the tray). Label the handle “B,” for
bottom.
3. Get the second strip of tape, and fold it in the same way. Place it on top of the first piece of tape, and label the handle “T,” for
top.
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Getting a Charge Out of Tape
54. Using the non-stick handles, lift both pieces of tape off the desk at the same time. Then touch the entire length of the strip on both sides with your fingers several times.
5. Pull the pieces of tape apart, making sure to not touch the tape anywhere except on the non-sticky handles you made. 6. Both pieces of tape are now charged. Experiment with your partner to see how the pieces of tape interact with each other when you bring them close together in different combinations. Slide6
Talk and write your observations
What happens when you bring the pieces of tape close together in each combination (T-T, B-B, and B-T)?Based on your observations, what patterns can you identify when two pieces of electrically charged tape are attracted to each other and when they are repelled? What causes the T and B pieces of tape to move toward or away from each other?
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Students’ models
Develop a model to explain the observations of how the scotch tape strips interact with each other.7Slide8
Developing a Scientific Model
The model is a simplified representation of a system or phenomenonCentral features of the model are made explicit and visible (including those that are not visible with eyes only) – components of the modelThe model allows to say something (explain) about what is happening –
relationships among the components of the modelAppropriate
labels
are included to clarify the model’s components Slide9
What
you may know from prior experience as a science teacherAll objects are made of particles/atoms.Particles/atoms are made of positive and negative charges.
Same charges repel; opposite charges attract.This behavior is similar to magnetism.
At this point,
we may
not be able to explain how neutral objects become charged, or why neutral and charged objects are attracted to each other.
In order to answer these questions and explain the observed phenomena, students need to understand atomic structure
.
(This is NOT an elementary topic but it is something we can try to understand as adults)
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Examples of students’ models
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Summary of students’ ideas from prior knowledge and scotch tape investigations
Objects can be positively charged (+), negatively charged (-), or uncharged (neutral).Objects with the same charge repel each other; oppositely charged objects attract each other.Students may also say…The distance between charged objects affects the interactions between them. The closer they are, the stronger the interaction.The amount of charge on charged objects affects the interactions between them. The greater the charge, the stronger the interaction.
Charged objects generate an electric field in the region around them.
It is through the electric field that charged objects interact with each other.
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