Do bars of soap sink or float?  My kindergarten scientists turned to those sitting beside them and discussed their ideas. Four of the bars sand (including Dove and Dial), but the bars of Jergens and Ivory soap floated. Another scientific discussion followed as the children tried to determine why one bar of soap would float while the other would sink. We concluded that two of the bars must be less dense than water. If it is less dense, could there be air bubbles inside? So, what would happen if we heated the Ivory soap in the microwave for one minute and thirty seconds? Look at the before and after pictures below. There is water trapped inside the air bubbles. When it is heated, the water molecules spread out into a gas and the soap expands because the heat has caused it to become more pliable too. Of course, we had to touch it! The texture surprised us because although it looked like whipped cream or snow, it didn’t feel like those at all. My scientists described the texture as soft, dry, and crumbly. Click here for more information about this investigation.