> Bismuth was long considered the element with the highest atomic mass that is stable. However, in 2003 it was discovered to be extremely weakly radioactive: its only primordial isotope, bismuth-209, decays via alpha decay with a half-life more than a billion times the estimated age of the universe. Because of its tremendously long half-life, bismuth may still be considered stable for almost all purposes.

I learned something new -- Bismuth is technically radioactive.

Bismuth is probably my favorite element, because of the beautiful way it crystalizes and the beautiful colors it has. Beyond the beauty it's also remarkably non-toxic considering its siblings, a form of it is a useful medicine when traveling, and it's more dense as a liquid than a solid like water. It's a really fascinating element. I really recommend reading about bismuth, at least this article, since the article does a good job of explaining a lot of its interesting aspects.