Atomic Number 115 Isotope 291, Periodic Table
Ununpentium, now known as Moscovium, is a superheavy synthetic element with symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia and was officially named on 28 November 2016. It is a member of the 7th period and is placed in group 15 as the heaviest pnictogen.
Moscovium is considered to have some properties similar to its lighter homologs such as nitrogen, phosphorus, arsenic, antimony, and bismuth, and to be a post-transition metal, although it should also show several major differences from them.
In 2011, the Joint Working Party of international scientific bodies, the International Union of Pure, and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) evaluated the 2004 and 2007 Dubna experiments and concluded that they did not meet the criteria for discovery. But in December 2015, the IUPAC/IUPAP Joint Working Party recognized the element’s discovery and assigned the priority to the Dubna-Berkeley collaboration of 2009–2010, giving them the right to suggest a permanent name for it.
In 1979 IUPAC recommended that the element name ununpentium (with the parallel symbol of Uup) should be used until the discovery of the element is confirmed and a permanent name is decided. On December 30, 2015, the discovery of the element was recognized by the International Union of Pure and Applied Chemistry (IUPAC). According to IUPAC, the discoverer of a new element has the right to suggest a name. The Dubna team mentioned the name moscovium several times as one among many possibilities, referring to the Moscow Oblast where Dubna is located.
Moscovium is expected to be in the middle of an island of stability centered on copernicium (element 112) and flerovium (element 114): the reasons for the presence of this island, however, are still not well understood. Although the known isotopes of moscovium do not actually have enough neutrons to be on the island of stability, they can be seen to approach the island as in general.