Astatine Element Number 85 At 

Astatine is the rarest natural element on earth. Astatine is a decay product of heavier elements, and has a very short half life. Maybe this 0.1 gm Uranium salt sample has 1 or so Astatine Atoms??

At 85 Halogen MP:576  BP:639  Unstable  AW:210 Half life 12 hours

Astatine is the rarest element on earth estimated at 28 grams at any given time on the surface crust. In nature Astatine is a byproduct of heavier element decay, and has a very short half life. The element is a halogen and very radio active. Only Francium has shorter half life than Astatine. Because Astatine is a decay product of Uranium and Thorium, either of these elements could contain Astatine atoms in their mass as a spontaneous fission product.

Astatine can be produced in laboratories, and until recently most of the information on Astatine was basically assumed.  Astatine research has given us a bit of information about this element. As halogens go, Astatine is least reactive, and shows more metallic properties than other halogens. Astatine can form a few compounds with Hydrogen, a few other elements, and also other halogens, to form inter-halogen compounds.

Astatine is a very radioactive alpha emitter, and decays to Bismuth, Polonium, Lead, and finally to a Thallium isotope. Bismuth is the element used to create Astatine by hitting the Bismuth with alpha particles with a cyclotron. The Astatine isotope produced depends on the energy of the alpha particles.

Because of Astatine's short half life it is used in radio medicine, Like Iodine, Astatine will accumulate in the thyroid gland, but has a much shorter emission distance, meaning the particles travel a shorter distance from the element's atoms.  Astatine has such a short half life it must be created, seperated from other isotopes, and then used quickly, This makes for exotic medicine!

I like to believe I have 3 or 4 Astatine atoms around my heavier samples at any given time.

 

Radon Element Number 86 Rn 

 This vial contains Thorium salts, and is sealed tight. I like to imagine the Radon gas atmosphere is at a constant equilibrium as a decay product of the Thorium.

Rn 86 gas liquid density 4.4 MP:-96.07  BP: 79.10 unstable AW:222 half life 3.8days 

The gasseous element Radon is a common household name, yet most who talk about this element know very little about it. Radon is a dangerous radioactive gas, which is a decay product of  Thorium.  Radon gas is