|Atomic mass||210 amu|
|Date of discovery||1940|
|Name of discoverer||D. R. Corson|
|Name origin||From the Greek astatos.|
Astatine is extremely rare in nature, and in fact, there is only about an ounce (about a teaspoonful) in the earth's crust at any one moment. It may be prepared in the lab, but still only in very small quantities. Not much is known about the physical properties of astatine because of its rarity and short half-life. One may speculate that it would react similarly to iodine, and following the periodic trend, astatine would presumably sublimate into a dark purple or blue gas, and have a dark metallic luster when solid.
Astatine is far too rare to have any uses, but some researchers think that astatine would behave like iodine. If so, it could be used to treat certain diseases of the thyroid, such as thyroid cancer. When swallowed, the astatine would go to the thyroid. There, the radiation it gives off would kill cancer cells in the gland.
|Periodic Table of the Elements|