| ||||||||||||||||||||||||||||||||||
Americium (95Am) 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 241Am in 1944. The artificial element decays by ejecting alpha particles. Americium has an atomic number of 95 (the number of protons in the nucleus of the americium atom). Despite 243
Am being an order of magnitude longer lived than 241
Am, the former is harder to obtain than the latter as more of it is present in spent nuclear fuel.
Eighteen radioisotopes of americium, ranging from 229Am to 247Am with the exception of 231Am, have been characterized; another isotope, 223Am, has also been reported but is unconfirmed. The most stable isotopes are 243Am with a half-life of 7,370 years and 241Am with a half-life of 432.2 years. All of the remaining radioactive isotopes have half-lives that are less than 51 hours, and the majority of these have half-lives that are less than 100 minutes. This element also has 8 meta states, with the most stable being 242m1Am (t1/2 = 141 years). This isomer is unusual in that its half life is far longer than that of the ground state of the same isotope.
© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search