Q&A: How Could We Destroy a Galaxy and More...

As I understand it, stars engage in fusion for their lifecycle and create ever heavier elements in the process and at the end of their life lead gets made and this sets off a reaction that destroys them. Question, if lead (or whichever metal if I'm wrong on that) was artificially introduced, would that kick off the reaction that would end that star? I've never asked something like this so be gentle if I'm way off on the initial science. Thanks, Lew