Otto Hahn and Lise Meitner discovered element number 91 together.
Meitner was pressured by the Nazi ideology, Otto Hahn, and his colleagues to leave Germany because of her Jewish heritage.
Kaiser Wilhelm Institute
Even after Meitner left, they continued to write to eachother in secret about some of their work.
Dear Lise, I've been doing some experiments with decaying Uranium into Radon, but I've got some puzzling results. The Radon behaves like barium. I would appreciate your insight on the phenomenon. -Otto Hahn
Hahn encountered results in his studies that he could not explain. He asked Meitner about it and she came up with a revolutionary theory that explained it.
Dear Otto, I find the results of your experiments to be intriguing. Maybe your "Radon" is actually Barium. Maybe in the right conditions, an atom sufficiently unstable could be split in two. -Lise Meitner
I'll call it nuclear fission!
Otto Hahn tested Meitner's theory and proved it to be correct.
E = mc2
He received great praise among the scientific community for his work, but he did not give Lise Meitner any credit.
Nobel Peace Prize Otto Hahn The Father of Nuclear Chemistry Awarded for great contributions in the field of chemistry, and the discovery of nuclear fission.