The first transuranium element was produced at the University of California at Berkley in 1940 by E. M. McMillan and P. H. Abelson. The transuranium elements are elements with atomic number greater than that of uranium (Z=92), the naturally occurring element of greatest Z. List of the transuranic elements by chemical series: 93 neptunium Np; 94 plutonium Pu; 95 americium Am; 96 curium Cm; 97 berkelium Bk; 98 californium Cf; 99 einsteinium Es; 100 fermium Fm etc.