Astatine (ˈæstətiːn or /ˈæstətɨn/) is a radioactive chemical element with the symbol At and atomic number 85. It is the heaviest of
Electron shell 085 astatine
the discovered halogens. Although astatine is produced by radioactive decay in nature, due to its short half life it is found only in minute amounts. Astatine was first produced by Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè in 1940. Three years passed before traces of astatine were also found in natural minerals. Until recently most of the physical and chemical characteristics of astatine were inferred by comparison to other elements. The alpha-emitting properties of some astatine isotopes are used for science applications, and also medical applications for astatine 211 are tested.

Characteristics Edit

This highly radioactive element has been confirmed by mass spectrometers to behave chemically much like other halogens, especially iodine (it would probably accumulate in the thyroid gland like iodine), though astatine is thought to be more metallic than iodine. Researchers at the Brookhaven National Laboratory have performed experiments that have identified and measured elementary reactions that involve astatine; however, chemical research into astatine is limited by its extreme rarity, which is a consequence of its extremely short half-life. Its most stable isotope has a half-life of around 8.3 hours. The final products of the decay of astatine are isotopes of lead. Following the color trend of the halogens, the elements get darker in color with increasing molecular weight and atomic number. Thus, following the trend, astatine is a nearly black solid, which, when heated, sublimes into a dark, purplish vapor (darker than iodine). Astatine forms ionic bonds with metals such as sodium, like the other halogens, but it can be displaced from the salts by lighter, more reactive halogens. Astatine can also react with hydrogen to form hydrogen astatide, which when dissolved in water, forms the exceptionally strong hydroastatic acid. Astatine is the least reactive of the halogens, being less reactive than iodine.


The base value of each unit of ranges between 1 and 50Ð per unit, with up to 3 units being found at any one time.

Presence on Mars: Very Rare

Martian Minerals
Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6
Group 3 |Antimony | Astatine | Barium | Bismuth | Cesium | Francium | Hafnium | Indium | Iodine | Iridium | Lanthanum | Lead | Mercury | |Osmium | Platinum | Polonium | Radium | Radon | Rhenium | Tantalum | Tellurium | Thallium | Tin | Tungsten | Xenon|