Americium is a chemical element. It is a radioactive metal. It has the chemical symbol Am. It has the atomic number 95. In chemistry it is placed in a group of metal elements named the actinides. Americium is a transuranic element (Transuranic means after uranium. All the elements used after uranium are man-made). It is a radioactive element that does not exist in nature. Americium has to be made. It has a silver color. Americium is made by bombarding a plutonium target with neutrons.