the highest atomic number of an element detected in laboratories is element 118, known as oganesson (Og). Oganesson was officially recognized by the International Union of Pure and Applied Chemistry (IUPAC) in 2016. It was named in honor of Russian physicist Yuri Oganessian, who made significant contributions to the discovery of superheavy elements.
Oganesson is a synthetic element that falls under the category of transactinides, which are highly unstable and have short half-lives. It is extremely difficult to produce and study these elements due to their high reactivity and short lifetimes. Oganesson is currently the heaviest element known, with an atomic number of 118. However, it's important to note that the synthesis and detection of elements beyond oganesson are subjects of ongoing scientific research, and future discoveries may extend the periodic table further.