Wow your students and anyone walking by your classroom.  Get a bar of Ivory Soap or 2 or 3 bars.

Why does Ivory Soap float? Ask your students.  Let them investigate different soaps.

Steve Spangler suggests you walk down the detergent isle and notice dozens of different kinds of soap. Green soap, smelly soap, big soap, even soap that floats.ivorysoap Ivory soap is famous for floating. How do they make some bars of soap float and others sink? Believe it or not, we’re going to cook the soap in the microwave oven to uncover the secret. Just wait until you see what happens when the soap that floats also cooks. You get a bar of soap that grows bigger than a football.


– Bar of Ivory soap
– Various bars of another brands of soap
– Deep bowl of water (or a plastic tub)
– Paper towel
– Microwave oven

Steve Spangler has directions and a great explanation for this investigation on his website.