Lesson 3 of 9
Objective: SWBAT demonstrate and explain what occurs when a positive charge meets a negative charge.
To begin the lesson, I ask students to refer back to what we learned about the north and south poles. We discuss the idea that opposites attract. We then review the north and south poles and how they attract and repel. I explain that we are now going to take that idea of opposites to understand how static electricity works. To do this I ask them to turn and talk to a partner to discuss what they know about static electricity. Some groups might discuss they idea that sometimes they get shocked when they touch something in their house. Most do not know why that happens or what causes it.
I now place my students into groups of two or three. I give each group a balloon (I have already blown them up for time and chaos sake). Students will need to now get out their science journal and label a fresh page with the title Static Electricity. They then need to draw the balloon and make a prediction on how the balloon might be abel to teach us about static electricity.
Next, I demonstrate how to how to charge the balloon. We are going to transfer energy and I do this by rubbing the balloon onto the carpet, wool would also work well too. Next it is partner one's turn to charge their groups balloon. I then ask the other partner to try and magically place the balloon onto the wall. I then tell the groups that they need to write what they observe into their science journal. I ask them to write the steps too. They would write: 1. rub balloon to charge 2. place balloon on wall 3. would be there observations.
I then ask the groups to choose three other items in the room to see if the balloon, once charged, sticks to them too. They need to track this data in their journal so that they know what stuck and what did not.
Writing to Explain
To explain what happened we now discuss the positive and negative charges between the balloon and wall. When we rubbed the balloon we created a negative charge and this is called static electricity. When it has enough charge, it will attract to a neutral surface like the wall by attracting the positive charges from the wall. This is similar to opposites attract. With the ballon being a light object it appears to magically stick to the wall. I ask the class to hypothesize why the balloon will eventually fall and not stay stuck.
To conclude the lesson, I ask the class to prepare to write. Now that they understand how and why the balloon sticks, I want them to expand their thinking to what happens when two balloons are charged. I explain the writing task. Each student will conduct their experiment and then write to explain why they think they got the results they did. This will be turned in. The task requires two groups to charge their balloons and try to stick them together. They will explain what happens and try to tell me specifically the why. I remind them to think back to our lesson on north and south poles.