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Silly Putty® Investigation

Students experiment with Silly Putty®, a silicone-based polymer that is highly elastic, but snaps when pulled quickly. It slowly takes the shape of its container, yet resists sudden forces like the blow of a hammer, and bounces very well. It is non-toxic and non-irritating to the skin.

Silly Putty® was invented by James Wright, a researcher at General Electric who was working on synthetic rubber substitutes in World War II. Mixing silicone oil with boric acid made the first Silly Putty® substance, and although it didn't work as a synthetic rubber, it did make a great toy!

There are other uses of Silly Putty®. At home, it can be used to pick up dirt and lint. Silly Putty® in various strengths is used to help people build up hand muscles after injuries. Because Silly Putty® adheres well, it was also used by Apollo astronauts to hold tools in zero-gravity!


  • Investigate the properties of a common polymer.


  • Per Class or Group:
    large bucket or tub
    metre stick
    tennis ball

  • Per Student:
    Silly Putty®

Key Questions

  • What makes Silly Putty® so special?
  • Is Silly Putty® a liquid, a solid or both?

What To Do

  1. Set up four experiment stations and have students circulate through them.
  2. Give students sufficient time at each station to experiment and respond to the key questions.
  3. Gather students together to discuss the results.

Station 1 (large bucket or tub, water)
• Does a blob of Silly Putty® sink or float?
• How could you make it sink or float if it doesn’t already?

Station 2 (metre stick, tennis ball)
• Does Silly Putty® bounce?
• If so, what fraction of its original height does it return to?
• Is this more or less bouncy than a tennis ball?

Station 3 (hammer or mallet)
• Can you flatten a blob of Silly Putty® with a mallet?
• Can you flatten it at all?

Station 4
• What happens if you pull the blob apart slowly?
• What happens if you pull the blob apart quickly?


  • Make a Silly Putty® tower or sculpture and let it sit undisturbed for a couple of hours. Does it hold its shape?
  • Examine the effect different temperatures have on the Silly Putty®.
  • How strong is Silly Putty®? Place differently-weighted objects on top of a ball of Silly Putty®. Examine and discuss the effects.
  • Use Silly Putty as a "cement" to build a straw structure. What properties of Silly Putty® make it a good building material? What properties of Silly Putty® make it a bad building material?

Other Resources

The University of Southern Mississippi | Polymer Science Learning Center | Make a Virtual Polymer