The chemical element with the highest atomic number is oganesson (Og), which has the atomic number 118. Discovered in 2002 and officially recognized in 2016, oganesson is a synthetic element named after Russian physicist Yuri Oganessian. It belongs to the noble gases group in the periodic table, although its properties may differ significantly from those of other noble gases due to relativistic effects on its electrons. Oganesson is highly unstable and has only been produced in minute quantities in particle accelerators, which makes studies of its characteristics extremely limited. Understanding its behavior helps scientists explore the boundaries of the periodic table.