- Included in the Scientific Posts List.
- Bismuth-209 has the longest half-life ever discovered of a naturally occurring element – 20,000,000,000,000,000,000 years.
Martin Winfree
December 11, 2012
However, science has marched on since then. Not only has the periodic table gotten a whole lot longer than it was when I was in high school, another low-numbered element, bismuth (#83) has been added to the list of those having no isotope that is not radioactive. You might remember that particular metal from the topical medicine that was popular when I was a kid, bismuth violet; it is also an ingredient in, and lends its name to medications such as Pepto Bismol. Scientists have long suspected that all isotopes of bismuth were radioactive, but it was only proved conclusively in 2003: Bismuth-209 has been determined to have the longest half-life ever discovered of a naturally occurring element – approximately 20,000,000,000,000,000,000 years. If that sounds like a long time, it is: That is more than one billion times the estimated age of the universe (13.75 billion years). How cool is that!
Martin Winfree
February 9, 2015
I eff-ing love science also! Check out this Wikipedia entry about bismuth, the next element up the periodic table from lead; it is present in several medicines, such as Pepto Bismol. Some understatement in the “slightly”, huh? 🙂
However, in 2003 bismuth was discovered to be slightly 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.