Since it was first synthesized in a post-WW2 American lab in 1949, berkelium has been a rebel of the periodic table, defying ...

“The discovery provides new understanding of how berkelium and other actinides behave relative to their peers in the periodic ...

Heavy actinides—elements at the bottom of the periodic table, after plutonium—are radioactive, rare and chemically complex, ...

That doesn’t make this gas any less heroic though: during the Cold War, its radioactive isotope Kr-85 was used to estimate how quickly the Russian government was building nuclear weapons.