Theoretically, there is no upper limit to the atomic number or weight of an element. However, as we move to higher atomic numbers, the stability of the elements becomes a significant concern.
Elements with extremely high atomic numbers would have a large number of protons in their nuclei, resulting in a very strong positive charge. This charge would cause electrostatic repulsion between the protons, making the nucleus unstable. As a result, these elements would have very short half-lives, meaning they would decay into lighter elements relatively quickly.
Additionally, the production of superheavy elements with high atomic numbers is extremely challenging. It usually involves the synthesis of new elements through nuclear reactions, such as bombarding a heavy nucleus with another nucleus to create a compound nucleus. The creation and identification of superheavy elements require sophisticated experimental techniques and facilities.
To date, the heaviest element officially recognized is Oganesson (symbol Og) with atomic number 118. It was first synthesized in 2002 and is highly unstable, decaying within a fraction of a second. Elements beyond atomic number 118 are yet to be synthesized and officially confirmed.
While it is theoretically possible to create elements with higher atomic numbers, the extreme instability and short lifetimes of these elements pose significant challenges for their synthesis and study. Therefore, the existence of an element with an atomic number of 200 or higher is purely speculative at this point.