- Astatine is a radioactive chemical element with the chemical symbol At and atomic number 85.
- It 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.
- It is the least chemically reactive of the halogens and exhibits the most metallic properties of the halogen group.
- The newly formed astatine-211 is
important in nuclear medicine. It can be used for targeted alpha