I have some strong toy neodymium magnets. Typically after a while little chips start breaking off, unlike from most other small metal objects, like in this image. It could of course be that neodymium is more brittle than metals used for other objects, or that they often hit each other much harde...

I have made a funny homemade experiment, repeatable, and with a high success rate over 6 bottles of cola. I haven't found any trace on internet. It reminds me the Mentos-Diet Coke experiment, but I am focusing on the lemon. Take a bottle of sugarfree cola, e.g. diet Pepsi in this case. Cut a lemo...