 Discovery Information |
| Who:
D.R.Corson
, K.R.MacKenzie,
E.Segre
|
| When: 1940 |
| Where: United States |
|
| Name Origin |
| Greek: astatos (unstable). |
|
| Sources |
| Does not occur in nature. Produced by bombarding bismuth with alpha particles. The longest-lived isotope, 210At, has a
half-life
of only 8.3 hours. There are about 20
isotopes
known, all of which are radioactive. Astatine is a
halogen
and possibly accumulates in the thyroid like iodine. |
|
| Uses |
| None. |
|
| Notes |
| With the possible exception of francium, astatine is the rarest naturally occurring element with the total amount in Earth's crust estimated to be less than 1 oz (28 g) at any one time; this amounts to less than one teaspoon of the element. Astatine is in "The Guinness Book of Records" as the rarest element on Earth. |
