Which element is between Uranium and Plutonium in the Periodic Table?
Plutonium Plutonium was first produced and isolated on December 14, 1940, by a deuteron bombardment of uranium-238 in the 1.5 metre (60 in) cyclotron at the University of California, Berkeley. First neptunium-238 (half-life 2.1 days) was synthesized which subsequently beta-decayed to form this new element with atomic number 94 and atomic weight 238 (half-life 87.7 years). Since uranium had been named after the planet Uranus and neptunium after the planet Neptune, element 94 was named after Pluto, which at the time was considered to be a planet as well. Wartime secrecy prevented its discovery being announced until 1948. Plutonium is the
Extended periodic table momentarily give an effective "Z" of 174; uranium with uranium gives effective "Z" = 184 and uranium with californium gives effective "Z" = 190). Supercritical atoms are hence expected to pose no difficulties with their electronic structure, so that the end of the periodic table may be determined instead by nuclear instability rather than electron shell instabilities. The stability of nuclei decreases greatly with the increase in atomic number after plutonium, the heaviest primordial element, so that all isotopes with an atomic number above 101 decay radioactively with a half-life under a day, with an exception of dubnium-268. No elements