Science Buddies: "Ask an Expert"

I am doing a science experiment to see how much salt is needed to conduct electricity for the squishy circuits. We followed the squishy circuit kit directions to make conducting dough and decreased the amount of salt by 1 Tbsp. each time. When we made the last dough with no salt, I was sure it wouldn't conduct, but IT DID! Why did it conduct electricity with no salt?

Hey there!

That is a great question! And what an interesting project as well. So, the short reason is because what you have created in that last dough is an "insulator". Insulators (examples of insulators are paper, glass, plastic, etc) will RESIST...not stop electricity from flowing through.

Here is some more information in a video on insulators and conductors using real life examples. It is important to note that in these examples the plastic and wood DO warm up, but not to the degree that the metals do.

https://www.youtube.com/watch?v=vfx8rVbWwmw

Great job with your project and question. Please let us know if any more come up.

Elizabeth

Hi aprillb34,

One important question - did you use deionized or distilled water to make your insulating dough, as described in the recipe? If you just use regular tap water, then impurities in the tap water will make the insulating dough much more conductive.

-Ben