The chemical element with atomic number 118. It is the heaviest known element. Highly radioactive, it does not occur naturally. Originally expected to be a noble gas, it is now predicted to be a reactivemetallicsolid, and a semi-conductor or a post-transition metal. [https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.201908327], "Oganesson Is a Semiconductor: On the Relativistic Band-Gap Narrowing in the Heaviest Noble-Gas Solids"
