It is certainly possible that there are elements in the universe that have not been discovered or fully characterized by scientists yet. Elements are defined by their atomic number, which corresponds to the number of protons in the nucleus of an atom. there are 118 confirmed elements, with the most recent addition being element 118, Oganesson (Og).
However, the exploration of the universe is an ongoing endeavor, and scientists continue to study and discover new phenomena. In theory, there is room for the existence of elements beyond the currently known ones, particularly if they have extremely high atomic numbers. The synthesis and identification of new elements is a complex and challenging process that often requires advanced technology and sophisticated experimental techniques.
It's worth noting that elements with higher atomic numbers become increasingly unstable and difficult to produce, making their discovery and characterization more challenging. Moreover, these superheavy elements typically have very short half-lives, which adds another layer of complexity to their study. Nevertheless, advancements in nuclear physics and technology may lead to the discovery of new elements in the future.
So while we currently have a periodic table with 118 confirmed elements, it remains possible that there are undiscovered elements in the vastness of the universe, waiting to be observed and studied by scientists.