To begin the lesson we review circuits and the elements that go into making them work. Students can use their notes from the previous lessons and experiments that are in their science journal. I really want to focus the discussion on how they built a working circuit.
When we complete the review, I split them into groups of three and four. I also given them the materials that are necessary for building an electromagnet. The materials we use came from the Foss kit on electricity and magnets. The materials are: large nail/rod, battery and holder, and a long wire.
Once every group has their journals and materials they are ready to try to make the electromagnet. I do not give them any information beyond what we reviewed about building a working circuit. This can be fun and frustrating. I am not expecting any of them to get it right away, but as I walk around I am looking to see if the groups remember how to attempt building the circuit. At about the half way mark I offer a hint. I tell them that when they wrap the wire around the nail, they need to wrap it in both directions.
With the magnets built students are taking turns picking up the tiny washers. I ask them to record how many they pick up with their magnet. Every group needs to draw a diagram of their completed electromagnet into their science journals. Underneath this diagram they will record the amount of washers it picks up.
After recording the number, I ask the class to try to rewrap their wire in hopes of changing the strength of the magnet. The challenge for the class now is to try to make it stronger and increase the amount of washers that it will pick up. I want students to try to add strength to the magnet to model how energy can be increased with a well designed plan. I also want them to understand that magnets can have varied strengths and be used for various purposes.
Students need to add notes and learning to their science journal. I ask them to make sure that they have a good diagram of the electromagnet that includes labels. Students should have washer amounts written inside as well. The last part is adding what they learned from building the magnet, including what they were trying and how they fixed it to make it work. They also need to add how they adjusted the wire to make it stronger. Any other connections or questions they still have are also important to write. If there is time I will have students share what they have written.