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 Make a paperclip float?

You can print these instructions out by choosing "PRINT" from your browser.

Impossible you say. A paper clip....float? Try it out!

You will need:

  • clean dry paper clips
  • tissue paper
  • a bowl of water
  • pencil with eraser

This is a simple experiment with impressive results:

  1. Fill the bowl with water
  2. Try to make the paper clip float...not much luck, huh?
  3. Tear a piece of tissue paper about half the size of a dollar bill
  4. GENTLY drop the tissue flat onto the surface of the water
  5. GENTLY place a dry paper clip flat onto the tissue (try not to touch the water or the tissue)
  6. Use the eraser end of the pencil to carefully poke the tissue (not the paper clip) until the tissue sinks. With some luck, the tissue will sink and leave the paper clip floating!

How is this possible? With a little thing we scientists call SURFACE TENSION. Basically it means that there is a sort of skin on the surface of water where the water molecules hold on tight together. If the conditions are right, they can hold tight enough to support your paper clip. Many insects, such as water striders, use this "skin" to walk across the surface of a stream. Want to make the surface of the water even stronger?

Have fun!
Science Bob

 

The project above is a DEMONSTRATION. To make it a true experiment, you can try to answer these questions:

1. How many paperclips can the surface tension hold?

2. Does the shape of the paperclip affect its floating ability?

3. What liquids have the strongest surface tension.

4. Can the surface tension of water be made stronger? (try sprinkling baby powder on the surface)

See if you can come up with more SURFACE TENSION experiments!