Unbiunium is a hypothetical (theoretical or imagined) element of the periodic table. It is also known as eka-actinium.
Its atomic number should be 121 and it has the symbol Ubu. The name Unbiunium and the symbol Ubu are temporary IUPAC names (meaning "one-two-one" in Latin). This name and symbol exist until a permanent name is decided and the element is created. It is expected to be a F-block element and in a group call the superactinides. It is the third element in the eighth period of the periodic table.
↑ 1.01.11.2Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN978-1-4020-3555-5.
↑Amador, Davi H. T.; de Oliveira, Heibbe C. B.; Sambrano, Julio R.; Gargano, Ricardo; de Macedo, Luiz Guilherme M. (12 September 2016). "4-Component correlated all-electron study on Eka-actinium Fluoride (E121F) including Gaunt interaction: Accurate analytical form, bonding and influence on rovibrational spectra". Chemical Physics Letters. 662: 169–175. Bibcode:2016CPL...662..169A. doi:10.1016/j.cplett.2016.09.025. hdl:11449/168956.