What I got for christmas, part 1.
It's a (synthetic) Bismuth (Bi) crystal. Now, Bistmuth, with atom number 83, was for long thought to be the last element with a non radioactive isotope. The next element in the periodic system is number 84, Polonium which is a nasty little bugger (killer of Litvinenko), followed by the extremely nasty, which I've already told you about, Astatine (85). And the rest of them are all radioactive as well, with no stable isotopes.
Turns out that Bismuth is not stable after all. The natural occuring isotope Bi-209
is actually radioactive, with a half-life of 13 700 000 000 000 000 000 years (a billion times longer than the age of the universe (compare that to the most stable isotope of Astatine, with a half-life of 53 seconds).
Nice to know that I now have a radioactive toy to play with. There are of course other radioactive substances in the household, Americium in the smoke detectors, and there probably also is some Radon sieving up from the ground. But this one is the only one I can hold in my hand.
I'm not particularly worried. Due to it's half life, it's radioactivity is almost undetectable (for all practical purposes it's stable). Besides it's an alpha-emitter. And alpha-particles have a very short range - they don't penetrate the most external, dead part of my skin. In short, I'm not afraid of dying (from my Bi crystal).
a pibbur who like everybody else don't have (and don't want) (and haven't seen) an astatine crystal.
PS. The last element with a stable isotope is now lead (atom number 82). DS.
PS2. A mixture of Bistmuth has been used for treating Helicobacter pylori infections, the most important cause of ulcers and other dyspeptic conditions of the stomach. I've used it once - it tastes
horribly. I still want to kill the guys who made it (perhaps not)
. DS.