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).
Isotopes of actinium Actinium (Ac) has no stable isotopes and no characteristic terrestrial isotopic composition, thus a standard atomic weight cannot be given. There are 31 known isotopes, from Ac to Ac, and 2 isomers. Two isotopes are found in nature, Ac and Ac, as intermediate decay products of, respectively, U and Th. Ac is extremely rare, and almost all natural actinium is Ac.