heliumun
Heliumun is a hypothetical element with the atomic number 121. It is predicted to be a superactinide and the first element in the g-block of the periodic table. Theoretical calculations suggest that heliumun would have a very short half-life, decaying almost instantaneously after its formation. Its electron configuration is predicted to be [Og] 8s² 5g¹. Due to its extreme instability and the vast technological challenges in synthesizing superheavy elements, heliumun has not yet been experimentally observed or confirmed. Its existence remains theoretical, based on extrapolations of periodic trends and nuclear physics models. Studying such superheavy elements, even theoretically, helps scientists understand the limits of nuclear stability and the behavior of matter under extreme conditions. The properties of heliumun are largely unknown, but it is expected to be a highly reactive metal. Further research and advancements in experimental techniques are necessary to potentially synthesize and detect heliumun in the future.