Unbiseptiumball

Unbiseptium, also known as element 127 or eka-americium, is the hypothetical chemical element with atomic number 127 and placeholder symbol Ubs. Unbiseptium and Ubs are the temporary IUPAC name and symbol, respectively, until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table, unbihexium is expected to be a g-block superactinide and the eighth element in the 8th period. Unbiseptium has attracted attention, especially in early predictions targeting properties of superheavy elements, for 127 may be a magic number of protons near the center of an island of stability, leading to longer half-lives, especially for 311Ubs or 355Ubs which may also have magic numbers of neutrons.

Early interest in possible increased stability led to the first attempted synthesis of unbiseptium in 1972 and searches for it in nature in subsequent years. Despite several reported observations, more recent studies suggest that these experiments were insufficiently sensitive; hence, no unbiseptium has been found naturally or artificially. The stability of unbihexium is also widely debated, as the island of stability may in fact lie at a lower atomic number, closer to copernicium and flerovium.

Unbiseptium is predicted to be a chemically active superactinide, exhibiting a variety of oxidation states from +1 to +8, and possibly being a heavier congener of americium. It is predicted to be the second element with an electron in a g orbital, a consequence of relativistic effects seen only in heavy and superheavy elements. An overlap in energy levels of the 5g, 6f, 7d, and 8p orbitals is also expected, which complicates predictions of chemical properties for this element.