Transoganesson elements are elements with atomic numbers higher than 118, that of oganesson. None of these elements were discovered yet, but the lightest members shall be discovered in the near-future. Elements higher than 172 would be grouped independently as transramson elements.
Transoganesson elements up to 172 are located in the 8th period and cross all five blocks of the extended periodic table, including g-block exclusive to those elements. This atomic number group comprises of five series: newtonide series (2 elements, 8s series), lavoiside series (22 elements, 5g series), dumaside series (14 elements series, 6f), kelvinide series (10 elements, 7d), and kirchoffide series (6 elements, 8p series).
Every element in this atomic number group are radioactive. Lighter elements in this group generally have longer half-lives than heavier elements. The longest-lived element is maxwellium (Z=126) with a half-life of 117 billion years; the shortest-lived is bunsenine (Z=171) with a half-life of just 117 nanoseconds. Lighter elements undergo mainly alpha decay while heavier ones undergo spontaneous fission.
Due to quantum and relativistic effects due to their high atomic numbers, many such elements differ considerably in properties from lighter elements in their corresponding families. As a result, electron configurations would differ than expected from Aufbau principle. For example, the g-block series would contain 22 elements instead of 18 because electrons are being added to other orbitals as the g-orbital should be focused.