The first man-made chemical element was that with atomic number 43. It was produced at the University of California Berkeley (by neutron bombardment of a molybdenum plate and was chemically identified at the University of Palermo (Italy) in 1937 by Segrè and Perrier. Previous attempts to identify it in natural ore had been unsuccessful, owing to the short life of its isotopes. Notwithstanding, several claims of its discovery had appeared in the chemical literature. The history of this discovery clearly shows the dramatic improvements of chemical analytical techniques and criteria in the first half of 20th century. In 1949 its discoverers proposed to call it technetium, which means produced by technology.