Plutonium
DOI: 10.1063/PT.5.031159
On this day in 1941, Glenn Seaborg and his team discovered element 94, plutonium, at the University of California, Berkeley. “It was the first synthetic element to be seen by man,” Seaborg wrote in 1981, and “the first realization of the alchemist’s dream of large-scale transmutation.” Plutonium gets its name from Pluto (which was then considered a planet), since the element follows uranium and neptunium on the periodic table. The discovery of plutonium remained secret throughout World War II—scientists referred to it by the code name “copper.” On August 9, 1945, the US dropped a plutonium bomb on Nagasaki, Japan. For the next week you can read for free a 1962 Physics Today article by Seaborg on synthesizing elements beyond atomic number 92, including plutonium.
Date in History: 23 February 1941
