 Glenn Theodore Seaborg ( / <unk> / ; April 19 , 1912 – February 25 , 1999 ) was an American chemist whose involvement in the synthesis , discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry . His work in this area also led to his development of the actinide concept and the arrangement of the actinide series in the periodic table of the elements . 
