The curious case of gak

We made a batch of gak - mixing cornstarch and water to make something between a liquid and a solid. Jr. scientist A had fun playing with it and making quite a mess. Jr. scientist E's reaction was very interesting. I dipped her hand into the gak slowly (making the gak act like a liquid) and then dipped her hand into the gak quickly (making it act more like a solid). She got a very curious look on her face when the previously liquid gak suddenly seemed solid. I think it dawned on her that something surprising was going on. It was pretty neat to see.

Hidden bubbles

We found this effect quite by accident. One of Jr. scientist A's new favorite things to do is to mix various ingredients together to see what happens - I think we have a budding chemist! We were adding things to red cabbage-dyed water (a pH indicator). As expected, when we added baking soda, the mixture turned blue, and adding vinegar to the same mixture caused it to bubble and then turn red. What caught us by surprise was that we next added salt and the mixture bubbled again. I had never heard of salt causing a chemical reaction resulting in bubbles, so we did some more investigating. Adding more salt turned the mixture from red (acidic) to purple, as would happen when you added a base, making us think that salt was a base (it's actually neutral). We tried combining vinegar and salt in another cup and got a rather unexciting cup of salty vinegar with no bubbles. After some google-ing, we found out that the salt wasn't actually creating bubbles, it was releasing the carbon dioxide bubbles trapped in our mixture after the baking soda and vinegar reaction. We decided to try adding salt to soda and got instant bubbles again. We even were able to create a little soda fountain (nowhere near as big as the mentos and diet coke reaction, but still cool). Jr scientists A and E both got quite a kick out of this accidental experiment, and I think it will become a new regular experiment.

Changing colors

Red cabbage juice is pretty cool. It changes color based on the pH of its environment. We got some dehydrated red cabbage juice powder in a science kit and decided to try it out. We mixed some of the powder and water in two cups, making some nice purple mixtures. We took our favorite acid and base (vinegar and baking soda, respectively) and added the baking soda to one cup and the vinegar to the other, getting bright blue and red mixtures (shown in the picture). Jr. scientist E was not impressed by the color changes, but Jr. scientist A really got into it. He immediately came up with a list of items to add to the mixture. We added baking soda to the vinegar mix, turning it back to purple (after the bubbles subsided). At Jr. scientist A's insistence, we added lemon juice, orange juice, flour, coffee, nuts, and various other things we had on hand - not a pretty mixture in the end but quite a crowd-pleaser!

Fizzy colors

Looking for a good experiment for Jr. scientist E, at my wife's suggestion I went back to an old fizzy standard - mixing baking soda and vinegar. To make it more interesting, I put down a drop of red food coloring and a drop of blue food coloring, with the baking soda and vinegar in the middle. As the fizzy mess spread, it took up the food coloring. Jr. scientist E just stared intently at the bubbly concoction (I think with interest!), getting transfixed each time I added more baking soda or vinegar to restart the fizzing.

Growing corn, a summary

Our corn growing experiment is finally at an end. We went from popcorn kernel to ears of corn. I have to admit I didn't imagine that we would actually pull this off. We knew almost nothing when we started - even mistaking the flowering part of the corn stalk for the corn - but with a lot of luck (and some research along the way), we actually grew corn. Jr. scientist A loved watching his corn grow and get taller than him. He was so excited when we got to pick the first ear of corn - he wanted to tell everyone! Now what can we try to grow next year?

Our experiment bears fruit (well, vegetables)

I didn't think it would work, but our corn experiment is actually starting to grow corn, and the tiny corn is getting bigger each day. The plants are now taller than jr. scientist A and are still growing. Who would have thought our humble little popcorn kernels would grow into this!

Making colored paper

We're trying to see how the sun affects different colored paper, so we decided to make our own colored paper with printer paper and food coloring. We cut strips of white paper and filled some shallow pans with water and food coloring. We let the strips soak in the pans overnight and moved them to wax paper the next morning to dry (flipping occasionally). Once they dried, we had pastel-colored paper!

Turning salt into glue

We tried to pick up ice cubes with string, using salt as the "glue." The idea is that, when you put salt on ice with the string resting on the ice, the salt lowers the ice's melting point, causing it to start to melt a little. As it refreezes, the ice freezes around the string. Our first attempt was a dud. You could feel that the string stick a little to the ice, but pulled right off. But it turned into an accidental experiment on states of matter - jr. scientist A was delighted to find that when he held the ice in his hand, it turned into water. For our second attempt, we realized that we needed to first wet the string. That turned out to be the key. With our salt and wet string, we were able to lift up the ice - although the effect was somewhat short-lived.

Mixing colors

Jr. scientist A got a science kit for his birthday that included pipettes and tablets to make colored water, so we started mixing colors together. It took some practice for him to get used to using the pipettes, but once he got it working, he was intrigued that mixing two liquids together created something that didn't look like either of the things he started with.

Making paper

For this experiment we turned paper into... paper. We started with some old newspaper and magazine pages and tore it into shreds (Jr. scientist A. is so good at doing that with paper he's not supposed to tear, but seemed unwilling to do it when he had permission!). We put the paper and some hot water in a blender, let it sit for 20 minutes, and then blended it into a watery mixture. We poured the mixture over a silk screen that was placed over a bin lined with a garbage bag. We then added leaves and a pressed flower we had collected on walks and pressed out some of the water. We let it sit in the sun, periodically pressing out more water. We eventually learned to put wax paper on top of the mixture before we pressed out the water after we kept pulling off parts of the "paper." After a day, it had dried and we carefully peeled it off the screen. We were left with (somewhat delicate) paper that had some of the leaf patterns pushed into the back side. A fun, albeit slow project.