How many meta states does the first isotope to be synthesized in Am in 1944 have?
Isotopes of americium Americium (Am) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no known stable isotopes. The first isotope to be synthesized was Am in 1944. The artificial element decays into alpha particles. Americium has an atomic number of 95 (the number of protons in the nucleus of the americium atom).
Nihonium Nihonium is a chemical element with symbol Nh and atomic number 113. It is a synthetic element and is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 8 seconds. Nihonium was first reported to have been created in 2003 by the Joint Institute for Nuclear Research in Dubna, Russia, and in 2004 by a team of Japanese scientists at RIKEN. In December 2015, the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) recognized the element and assigned the priority of the discovery to RIKEN. In November 2016, the IUPAC published a declaration defining the name to be "nihonium". The name comes from the common Japanese name for Japan (日本 , nihon ) . On 28 November 2016, the name became official.