Electromagnets! – For the Teachers

aka “Burning Student Fingertips, One Fifth Grader at a Time”

ElectromagnetsThis morning a friend of mine mentioned that her 4th grader daughter’s class was currently doing a science unit on magnetism and electricity, which immediately made me smile and launch into a long string of stories about my own students.

The magnetism and electricity unit has long been one of my favorites. It was one of the first science units I ever taught, back when I was student teaching in the mid-90’s. I loved it because there were so many opportunities for hands-on learning. At that time my dad helped me assemble a bunch of boards with light bulb holders and wires so that the students could make various parallel and series circuits. I used those boards for years, and we had a lot of fun with them. You know you a lesson is a winner when students choose to give up recess time to stay in class for more science. Perfect.

My favorite activity during this unit was our Electromagnet Contest. I gave the kids nails (several sizes), batteries of various sizes (up to 9 volt) and wires of varying gauge and color (in case that variable mattered too – some kids started the activity convinced the color would matter!) I also gave them boxes with hundreds of paper clips.

Their goal was to use the nail, wire and a battery to create an electromagnet strong enough to pick up the paper clips. The team that picked up the most paperclips with their electromagnet was the “winner.”

They experimented with all sorts of options: Did it work better if the wire was wrapped tightly or more loosely? Would more paper clips be picked up if they were linked together?

And they learned some interesting things. AA, AAA, C and D batteries, for example, have the same voltage. A bigger battery doesn’t necessarily mean more power.

Holding the tips of the wire to the ends of the battery created some heat, enough to be uncomfortable to hold – thus the burned fingertips. They tried electrical tape, alligator clips and other means of keeping everything in the circuit connected.

We figured out that if we put bandages on our fingertips, the bandages acted like an insulator. We could still hold the wire in place but without feeling the heat as much.

Our class record was 95 paperclips. Think your students could beat that?




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