Using the book 101 Cool Science Experiments with Glen Singleton, we just did the Bouncin Egg Experiment, and it was a major hit.
Very simply, you take two raw eggs and put one in plain water and the other in vinegar.
Then you monitor them every day for one week, writing down your observations. Each day I asked the kids to touch the egg and describe what they felt and saw. We talked about changes like “foaming vinegar” and “rubbery feeling shells” and tried to figure out what that would mean for our last day. We hypothesized about which egg would be “bouncy”.
Then, on the last day, we tried to bounce each egg. The kids were giddy at getting to throw them in the bowls. The egg in water cracked like a regular egg. But the egg in the vinegar bounced! The kids were mesmerized that they were able to change the egg from a “cracker to a bouncer”. We talked about what had happened – – the acetic acid in the vinegar reacted with the calcium carbonate in the shell. The hard shell dissolved, but the membrane surrounding the egg remained intact. It made the egg feel rubbery. For extra fun we squished the bouncy egg. Weren’t we surprised to learn that although it felt like it had turned to rubber, inside it was still mostly liquid! Prehaps next time we will leave them longer or use cooked eggs to see what happens. For now, the kids are so pleased that they not only got to “do real science”, as Molly put it but also that, as Joseph said, the did “magic”.