0 a chemical element that is radioactive and is the rarest natural element on the Earth's surface: --
The properties of astatine remain a mystery.
Astatine-219 decays to polonium-215, which itself beta decays to astatine-215 with an even smaller probability of 0.00023%.
The least stable one is astatine-214m1; its half-life of 265 nanoseconds is shorter than those of all ground states except that of astatine-213.
A visible piece of astatine would be immediately and completely vaporized due to the heat generated by its intense radioactivity.
The properties he reported for dakin do not correspond to those of astatine, and the true identity of dakin is not known.
Astatine may be dark, or it may have a metallic appearance and be a semiconductor, or it may even be a metal.
While hydroiodic acid solutions are stable, the hydronium-astatide solution is clearly less stable than the water-hydrogen-astatine system.
Francium is a highly radioactive metal that decays into astatine, radium, and radon.
Astatine, which is usually classified as a nonmetal or a metalloid, has been predicted to have a metallic crystalline structure.