I realize this is a very basic question, but I am a layman, and would appreciate a solution to my idle curiosity. Question occurred to me in the wake of the London spy incident.

Are there any elements (natural or man-made) which exist ONLY in radioactive isotope forms, that is, have no non-radioactive form?

every element above lead is radioactive in all isotopes discovered. so, quite a few to answer your question

as above with the exception of element 43 (Technetium) that exists as radioactive only. also it`s all elements after Bismuth, not Lead.

Its chemistry theres always exceptions to the rule.

 

BTW bismuth is radioactive in all isotopes, it just happens to have a half life several thousand million times longer than the age of the universe. source: http://physicsweb.org/articles/news/7/4/16

I hardly think that Qualifies! when you consider Many other elements classed as Non-Radioactive have much shorter half lives, such as Carbon or Nitrogen etc...

lets not play silly games and confuse the guy eh!

Thank you all very much for your clarifications and tolerance of lack of knowledge in this area.

 

By the way, "the guy" (me) is ALREADY pretty confused, so don't worry about it.

Welcome to the Forums

Unstable is still unstable, though. There are no stable isotopes of Bismuth.

I have following link for stable isotope of Bismuth :

http://www.britannica.com/eb/article-81026/nitrogen-group-element

weknowthewor, thats the isotope YT mentioned, it has since been proven to be radioactive and hence unstable.

from http://atom.kaeri.re.kr/ton/

 

Bi-209 been known as stable nuclide. But, alpha decay of Bi-209 with a half time of 2*10^19 years was found, recently.

Reference : PIERRE DE MARCILLAC, NOEL CORON, GERARD DAMBIER, JACQUES LEBLANC & JEAN-PIERRE MOALIC, " Experimental detection of a-particles from the radioactive decay of natural bismuth," Nature 422, 876-878 (2003); doi:10.1038/nature01541

thanks swansont, i already had a link to it further up the page.