Discipline: Physics, Life Science
Age Range: 5+ (with adult supervision)
Estimated Time: 5-10 minutes
What you need: a container of water, a small square of tissue paper or newspaper, a paperclip, and a pencil
What happens when you drop a paperclip into a bowl of water? Does it sink or float? Normally it sinks, but you can use science to make it float on the surface! Try this: cut out a small square of tissue paper and place it on the surface of a container of water. Place the paperclip on top of the tissue paper. Now, VERY gently and patiently, use the eraser end of a pencil to push the corners of the tissue paper down into the water. Slowly work your way closer and closer to the paperclip without touching it. Once most of the tissue paper is under the water, use the pencil’s eraser to gently push it all the way under the water. The paperclip should remain floating on the surface! It might take a little practice – don’t give up!
This works because of something called surface tension. The molecules in water are attracted to one another, kind of like tiny magnets. This creates a “film” or “skin” on the surface of the water which can be strong enough to hold up a paperclip. Surface tension also helps some insects, such as water striders, to move across the surface of the water!
Sources:
https://sciencebob.com/make-a-paperclip-float/
https://www.nwf.org/Educational-Resources/Wildlife-Guide/Invertebrates/Water-Striders
