Hi Readers! This is experiment #3 in our series of science from chemistry camp, talking today about things we can do with corn starch and different stages of matter.
One of the things that we spent a lot of time talking about during chemistry camp was different stages of matter, and particularly how things can transition from being a solid, to a liquid, to a gas, or back in the other direction. In some cases, like for “dry ice,” we can even skip the liquid stage entirely and go straight from the solid to the gas. This process is called “sublimation,” and for dry ice, it results in the release of carbon dioxide gas from the solid carbon dioxide pellets.
One topic that is particularly interesting in discussions of matter is non-Newtonian fluids, which are fluids that have properties of both liquids and solids, depending on the pressure that they are under. Our most favorite non-Newtonian fluid is “oobleck,” which is a mixture of corn starch and water. When you get the consistency right, oobleck is a liquid when there is no pressure applied to it, but behaves like a solid under higher pressure conditions.
Check out this photo of people running in oobleck for an example of how fun this can be:
However, in addition to creating oobleck out of corn starch, we can also create a play-doh simply by mixing corn starch with hair conditioner or other moisturizer. This additive creates enough structure between the corn starch molecules that they stick together without collapsing into a liquid consistency, regardless of the pressure that is being applied.
In chemistry camp, we used our corn starch “play-doh” to create volcanos, but the possibilities for what you can create with corn starch play-doh are endless!
Check out the links below for more information: