I have a newfew that's really into science stuff and I want to try doing things with him. I've never been much of a science guy myself but I thought it would be really cool to try dissolve a metal in something but I don't know what to use or how to do it safely. I have tons of old nuts and bolts lying around that I'm pretty sure are iron or steel. Does any anon know something I can do with it or any alternative at home experiments?