Element 85 (Astatine)

Astatine is a rare, naturally occurring element with the symbol At and atomic number 85. It’s a halogen, like iodine and fluorine, and exists only in trace amounts within Earth's crust. Astatine is solid at room temperature but highly unstable, meaning it quickly decays into other elements. Because of this, it’s challenging to study directly. Despite its scarcity, scientists are interested in astatine for potential medical applications, such as targeted cancer treatments, due to its radioactive properties. Overall, astatine is a rare, radioactive element with special theoretical and practical significance.