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 rhodium Naturally occurring rhodium (Rh) is composed of only one stable isotope, Rh. The most stable radioisotopes are Rh with a half-life of 3.3 years, Rh with a half-life of 207 days, and Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (Rh) to 121.943 u (Rh). Most of these have half-lifes that are less than an hour except Rh (half-life: 20.8 hours) and Rh (half-life: 35.36 hours). There are also numerous meta states with the most stable being Rh (0.141 MeV) with a half-life of about 3.7 years and Rh (0.157 MeV) with a half-life of 4.34 days.