I split my class into groups of two and three to begin. I start by explaining to the class that the experiment they are going to conduct is going to require them to design a system for sorting out salt and pepper once its been mixed. They are only to get a tool to help them, but they can only use this one tool. I unveil the tool dramatically. They are shocked to see that it is a white plastic spoon.
Students will now design a plan. To do this I walk around and place on their working spaces salt and pepper. I keep them separate so that students can observe them better in order to plan more extensively. I then give each group time and ask that they write their ideas into their science journals. The group needs to agree on the plan. Once they have they need to mix the salt and pepper.
Once I have seen each groups plan, I do a quick check of their ideas and let them give their plan a try. This is fun to watch because most of them are trying some way to scoop and sort out the pepper and salt. Once some time has gone by, I ask the class to come together with me for a discussion.
To begin, I ask them to tell me how their plan was working out and if any of them have successfully separated their substances. I then ask them to now use what they know about static electricity to explain how we might make a new plan. Before we share our ideas with the whole class, I ask each group to try to figure out how we might use static electricity.
I then bring the groups together and ask them to share their ideas. This collection, collaboration and sharing is critical to thinking out a successful process. Instead of giving them an obvious hint, I facilitate the discussion and help them understand that they can charge the spoon. We review what we know about the positive and negative energy around objects and how these two opposites attract.
Students are ready to now try out the charging of their spoons. I remind students that they need to look back in their notes at the balloon experiment they conducted to learn about static electricity. Students are getting the hang of it and begin to notice that the pepper will cling to the spoon, making it easier to sort it out.
With each group having success, I bring the group back together. I run through the experiment again and model how I charge the spoon to then get the pepper to "jump" to the spoon by barely hanging it over the pepper and salt. We discuss how static electricity helped us sort out the pepper. We also discuss why the pepper "jumped" to the spoon but not the salt. This led us to a great conversation on weight/ mass of an object.
To complete the lesson, I ask the class to write down what they learned into their science journals. I remind them to connect to the static and balloon lesson to explain what happened.