Ivory Soap Science!

6 11 2008

ivory-soap-experWe found a really easy experiment on the Steve Spangler Science website that produces amazing visual results! All you need is a microwave, a plate, and a bar of ivory soap!


  1. Place an unwrapped bar of ivory soap on the center of a plate.
  2. Put the plate of soap in a microwave.
  3. Cook the bar of ivory soap in the microwave for up to 2 minutes.
  4. Watch as the soap expands into what looks like a giant, puffy cloud!
  5. Take the plate out of the microwave. Once the soap has cooled, feel the soap- as Steven Spangler explains, the soap will feel “puffy but rigid.”

So how does this awesome experiment work? Ivory soap is known as “the soap that floats.” Ivory soap is full of air bubbles that are pumped into it when it is made. The air makes the soap less dense, or less heavy, so since the soap is very light, it is able to float on water. Ivory soap expands in the microwave because it contains water that is trapped inside all the air bubbles of the soap. When the water in the air bubbles becomes hot, it vaporizes and expands causing the soap to “grow.”




One response

19 02 2009

We at Steve Spangler Science love that you picked this experiment to feature. This is a great experiment to do at home. And it doesn’t wreck your microwave like some other things can. Here’s another experiment about water in the microwave. It isn’t one to perform at home, but a good lesson to look at http://www.stevespanglerscience.com/experiment/exploding-water-in-the-microwave

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: