Astatium

Astatium is a hypothetical element with the symbol At and atomic number 116. It is predicted to be a member of the superactinide series. As a superheavy element, astatium would be highly unstable and radioactive, with a very short half-life. It is unlikely to exist in significant quantities in nature, and if synthesized, would decay very rapidly. Theoretical calculations suggest that astatium would be a solid at room temperature. Its chemical properties are predicted to be similar to the lighter halogens, though relativistic effects at such a high atomic number could lead to deviations. Astatium is not a naturally occurring element and has not been experimentally confirmed or synthesized. The name "astatium" is derived from the Greek word "astatos," meaning unstable, reflecting its predicted properties. The discovery and characterization of elements beyond uranium, particularly the superheavy elements, are areas of active research in nuclear physics and chemistry. Future experiments might attempt to synthesize astatium to verify theoretical predictions.