Floating
Paper Clip
What You'll Need
Directions
What
Happened?
-
Bowl
-
Water
-
Paper Clip
-
Tissue Paper
-
Toothpick
GRADE
K-2
TIME
5 min
-
Fill a bowl with water about ¾ full.
-
Place the paper clip on the top of the water, and watch as it sinks.
-
Remove the paper clip from the water.
-
Tear a small piece of tissue paper (a rectangle a little larger than the paperclip will suffice).
-
Place the piece of tissue paper on the surface of the water so that it floats.
-
Dry the paper clip, and place it on top of the tissue paper so that it also floats.
-
Use the toothpick to push the tissue paper to the bottom of the bowl, but make sure that you do not touch the paper clip while doing this.
-
Now, watch as the paper clip floats on the water’s surface.
-
This process may take a few tries, so if you accidentally knock the paper clip to the bottom of the water, repeat steps 4-8 with a new piece of tissue paper.
This experiment works due to surface tension, a force that holds liquids together. In this case, imagine the water molecules (very small particles of water) on the surface holding hands. When you initially put the paper clip in the water, you broke this tension, so the molecules couldn’t hold hands. However, with the help of the tissue paper, the tension remained intact, so the water molecules were able to keep holding hands and support the paper clip.