the highest atomic number of any element discovered and officially named is 118. This element is called Oganesson (symbol Og) and is named after Russian physicist Yuri Oganessian. Oganesson belongs to the noble gases group on the periodic table.
Oganesson is a synthetic or artificially created element, and its most stable isotope, Oganesson-294, has a very short half-life of a few milliseconds. Due to its high atomic number, Oganesson is expected to be a member of the superheavy elements and is classified as a transactinide. It is situated in the seventh period of the periodic table, which indicates that it would have seven electron shells surrounding its nucleus.
Since Oganesson is highly unstable and has a very short half-life, its chemical and physical properties have not been extensively studied. However, being a noble gas, it is expected to have similar properties to other noble gases such as helium, neon, argon, krypton, xenon, and radon. These properties include being chemically inert, having low boiling points, and being monatomic gases under standard conditions.
It is worth noting that the discovery and exploration of new elements beyond Oganesson is an active area of research in nuclear physics, and future discoveries may expand our understanding of high atomic number elements and their properties.