Element Americium, Am

The member of actinide or actinoid group of chemical elements - Americium was synthesized in 1944-45 by Glenn T. Seaborg, Ralph A. James, and Leon O. Morgan, at the Metallurgical Laboratory of the University of Chicago by irradiation of Plutonium with neutrons. After americium discovery it became clear that the heavy transuranium elements are members of series similar to that of rare-earth elements, lanthanoides. From element to element the 5f-shell is being filled like the 4f-shell of lanthanoides. Americium contains six 5f electrons, and it is similar to europium which contains six 4f electrons. That was the reason to name the element number 95 americium after America as europium was named after Europe.

Americium does not have stable isotopes and therefore not detected in nature.