Lately we have focused on states of matter in our experiments. We have studied solids (here), liquids (here and here) and gases (here) as well as transformations between these states of matter (here and here). One substance we found that was in between liquids and solids was magic mud. Magic mud is created when you combine corn starch with water. The recipe we used was 5 tablespoons of corn starch and 3 tablespoons of water. However, daughter wanted to have a coloured magic mud and, as we didn’t have any food colouring, I used juice made from berries instead of water. I also wanted to tweak with the consistency a bit, so I added a bit of water and then some corn starch to get a consistency I was happy with.
It was quite tricky to mix with a spoon as it really wanted to behave like a solid. But then it flowed when next to no force was applied. We played with the magic mud, prodded it, poked it, hit it etc. basically studied it and discussed about liquids and solids. It fills the container it is in, which is what liquids do. It flows when moved slowly or left to drip, also something liquids do. But when you hit it hard, it goes nowhere but stops the movement, which is more what solids do. It does not flow around an obstacle (when the obstacle moves fast), which is also a more solid thing. Daughter commented that it really looks like liquid but on the inside (at its heart) it is solid.
Cleaning it up from the stove was quite tricky as it did not act clearly as either solid or liquid but was both. This meant that it flowed in front of the towel, but stuck to the stove when I applied pressure to get it off. This is something we will play with more as it is quite a weird substance.
If you try these experiments at home and your child asks questions, please let me know what types of questions they ask in the comment section so I can further develop these instructions. If you have questions about these experiments or instructions, leave me a comment and I will answer and also improve these instructions. Also, please remember like and share if you find this useful.
Copyright text and images: Satu Korhonen. You are free to try these experiments out, use them in your teaching. But instead of copying the text or images, link back to this page.