Unbinilium is the 120th element in the periodic table with the symbol Ubn.
It has not yet been discovered but if it were, it would be the second element in the eighth period of the periodic table and that it is possibly a radioactive alkaline earth metal. The nomenclature Unbinilium and Ubn are the temporary systematic IUPAC name and symbol until a permanent name is decided.
Previous experimental evidence showed that the period 8 elements will likely be far more difficult to synthesize than the previously known elements and that Unbinilium may even be the last element that will be synthesized with modern technology. Attempts to synthesize element 120 push the limits of current technology, due to the decreasing cross sections of the production reactions and their most likely short half-lives.
In March-April 2007, the synthesis of element 120 was attempted at the Flerov Laboratory of Nuclear Reactions in Dubna. They decided to bombard a plutonium-244 target with iron-58 ions. The preliminary analysis revealed that no atoms of element 120 were produced providing a limit of 400 fb for the cross section at the energy studied. The GSI repeated the experiment with a higher sensitivity in three separate runs from April/May 2007, Jan/March 2008, and Sept/Oct 2008, but all of them gave negative results and provided a cross section limit of 90 fb.
Unbinilium
Unbinilium is expected to be less reactive than barium and radium and closer in behavior to strontium. In addition, though it should show the characteristic +2 oxidation state of the alkaline earth metals, it is also predicted to show the +4 oxidation state unfamiliar in any other alkaline earth metal.
Unbinilium may be produced by nuclear fusion. These types of fusion reactions can be divided into Hot and Cold fusion, depending on the excitation energy of the compound nucleus produced. In hot fusion reactions, high-energy projectiles are accelerated toward very heavy targets, giving rise to compound nuclei at high excitation energy. In cold fusion reactions, the fused nuclei produced have a relatively low excitation energy which decreases the probability that these products will undergo fission reactions.