Recently Leah has been saying that she wants to be a scientist when she grows up.  I’m definitely planning on encouraging this dream.  First of all, the United States needs more women in science.  Second, this is a huge improvement over her previous dream of becoming either a mermaid or a cheerleader when she grows up.

So, when I heard about this easy, fun experiment, I knew we had to try it for New Experience #51.

All we had to do was put a bar of Ivory soap in the microwave for 2 minutes and watch it expand into a foamy cloud.  But, the teacher in me needed to add a little more learning to the explosion.

I took out a bar of Dove soap and Ivory soap.  We compared their color, shape, and weight. Next, we put each bar into a pot of water.  The kids noticed that the bar of Dove soap sank to the bottom while the bar of Ivory soap floated to the top.

Next, we put the bar of Dove soap in the microwave for 2 minutes.  We watched it melt for about a minute and a half.   With just 30 seconds left, it started to foam a bit.  The kids were impressed, so I couldn’t wait for them to see what would happen to the Ivory soap.

We put the bar of Ivory soap into the microwave.  Within twenty seconds, it started to foam.  It continued to foam and expand.  After a minute, my ever-cautious son thought we should stop the microwave.  He was afraid it might explode.  I told him we needed to keep the bar in for 2 minutes because we needed to do exactly the same thing with the Ivory soap as we did the Dove bar.  He looked at me skeptically and asked for goggles.  By the time he finished his sentence, the Ivory soap had just 10 seconds left on the timer.  I distracted him by starting a countdown, and he was once again excited to see the soap expand.

It really was impressive.  The Ivory soap expanded so much that it overflowed from the bowl.  The kids couldn’t wait to touch it.  We were all surprised that it was not as soft as it appeared.  It felt as dry as the original bar of soap.

By the time the Ivory soap was back on the counter, the Dove soap was no longer puffy.  It looked more like melted soap.  In contrast, the Ivory soap stayed puffy-looking all evening.

We added to our comparison chart, and I asked the kids why they thought one soap expanded while the other did not.  I reminded them of how one soap sank to the bottom while the other floated.  They figured out that the Ivory soap must have air inside it.

Here is the scientific reason this experiment works:  The Ivory soap has air bubbles inside it.  The air bubbles also have water inside them.  The water expands, which then causes the air bubbles to expand and make the bar of soap lose its regular shape.  That is the very simple explanation.   Steve Spangler Science has a much more detailed scientific explanation.  However, I thought it was a little advanced for my children, and probably above my level of understanding, too!

Both of my children enjoyed this experiment, but Leah absolutely loved it.  I told my budding scientist that we will definitely do more science experiments in 2013.

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