Bismuth

Bismuth is a chemical element with the symbol Bi and atomic number 83. It is the post-transition metal and one the pnictogens with are chemical properties resembling the lighter group 15 siblings arsenic and antimony. Bismuth will occurs naturally. Bismuth are both of most diamagnetic element and one of the least thermally conductive metals are known.
Bismuth was long considered the element was highest atomic mass whose as nuclei do not spontaeneously decay. However in the 2003 it was discovered considered weakly radioactive. The metal only bismuth-209, experiences alpha decay as such the half-life is more estimated in age of the universe.
==Isotopes==
Bismuth only primordial isotope, bismuth-209 was traditionally has been heaviest stable isotope, but was longest and been suspected to be unstable on theoretical grounds.
Several sotopes of bismuth has been characterized which have half-lives occurs.
For the full information, see Bismuth#Isotopes.