Appearance and Characteristics
Harmful effects:
Highly radioactive
Characteristics:
Astatine is highly radioactive and is only available in tiny quantities. Its properties are inferred from its position in the periodic table and by studying its chemistry in extremely dilute solutions.
Like the other halogens, astatine would be expected to form salts with metals such as sodium. Astatine can also react with hydrogen to form hydrogen astatide, which when dissolved in water, forms hydroastatic acid.
Astatine is the least chemically reactive of the halogens and exhibits the most metallic properties of the halogen group.
Uses of Astatine
Astatine-211 is sometimes used as a radioactive tracer and in cancer treatment. Like iodine, it is known to accumulate in the thyroid gland.