Like a lot of homeschoolers, we do most of our science in the kitchen. Gunnar and I cooked up this little project together. Do you know what it is?
Yah, it's a foam - a closed-cell foam.
Here's how we made it:
Much to his delight, Gunnar got to use his new knife (no kitchen knife for him) to cut a chunk off a bar of Ivory soap. (Must be Ivory - other soaps won't work.)
This, of course, required much cleaning of the blade of the *NEW* knife.
That accomplished, we popped the soap into the microwave and turned it on.
Immediately the soap began to grow!
We had to stop the experiment, midway, to scoop the soap back onto the plate.
(And I hope you appreciate that I'm keeping it real here... IOW, yes, I know the micro needs to be cleaned. Badly.)
The soap maxed out its size in about a minute.
When we heated the soap it softened and became more pliable. The air and water trapped inside the soap were also heated. The water vaporized and expanded, causing the soap to expand and become a foam. The finished product - the foam - cooled, shrinking slightly, and became firmer again.
Science nerd question -
was this a physical change or a chemical change?