Currently berkelium is synthesized by bombarding the element americium with alpha particles. It was the fifth element of its kind to be synthesized, and it was first synthesized in 1949; at that time, berkelium was synthesized and isolated using an isotope, number 241, of americium. The americium isotope was bombarded with alpha particles which produced an isotope of berkelium, number 243, that had a half life of 4.5 hours. Alpha particles are formed from two protons and two neutrons that closely resemble the nucleus of the element helium. Alpha particles are created by radioactive nuclei from elements such as uranium or radium during the process of alpha decay. Different chemical forms of berkelium have been identified using x-ray diffraction; some of these forms included berkelium oxychloride, berkelium fluoride, berkelium dioxide, and berkelium trioxide. Some predicted isotopes of berkelium have half lives that could last up to 1380 years, but the majority of the isotopes of this element have half lives of less than 5 hours. The shortened half life makes isolation procedures especially difficult.
