Materials (for each child):
1 paperclip with a piece of thread tied to it
2 paper cups
2 popsicle sticks (we used large ones, might want 3 small ones)
The night before I practiced getting the paperclip to float in the air without touching the magnet to it. I did this with my six year old son to make sure that the kids would have enough dexterity for this. No problem! He insisted that I should make this a “surprise” science experiement like the last one and not tell them in advance what would happen. This was the best advice. Just like with software user interface design, I found that usability testing the science experiment in advance greatly improved my lesson plan.
First I held one end of the thread showed everyone the paperclip hanging from it and I asked the students to tell me what they observed. They noticed a paperclip and that it was tied to a piece of string. I pointed out that the paperclip was hanging down. I asked them if anyone knew what we call the force that makes it hang down. I let them talk about gravity for a bit and what would happen if there was no gravity.
I asked how might we make the paperclip hang to the side or hang upward. One boy suggested that if we put it in water it would float, so we did an experiment with a cup of water – no luck. The kids were all out of ideas. I pulled a magnet out of my pocket (which they readily identified from a previous science class) and proceeded to demonstrate.
One reader, Charles Tucker, commented that “you do not need 2cups you need none and you do not need popcicle sticks either.” Let me explain my descision here.
It is true that you can do this by just holding the magnet, but for first graders, it is easier to set up and hold it steady with the popsicle sticks and the cups. After they have the paperclip floating in the air, they can experiment with what kinds of materials disrupt the magnetic field: using another popsicle stick, a washer, etc.
inspired by Top Science Magnetism #33