Floating Paper Clip
The metal clip floats.
Teaching & key ideas
What you do: Gently lower a paper clip flat onto the water.
What students see: The metal clip floats.
Why it works: Surface tension supports the clip if the surface isn't broken.
Question to ask: Why can heavy metal stay on top?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why can heavy metal stay on top?