Friedrich Wilhelm Strassmann (; 22 February 1902 – 22 April 1980) was a German chemist who, with Otto Hahn in December 1938, identified the element barium as a product of the bombardment of uranium with neutrons. Their observation was the key piece of evidence necessary to identify the previously unknown phenomenon of nuclear fission, as was subsequently recognized and published by Lise Meitner and Otto Frisch. Personal life and education Strassman was born in Boppard, Germany, to Richard Strassman and Julie Strassmann (née Bernsmann). He was the youngest of nine children. Growing up in Düsseldorf, he developed an interest in chemistry at a young age and conducted chemistry experiments in his parents' home. His family was of modest means, and his father died at a young age, worsening the family's financial situation. Financial considerations limited Strassmann's initial choices of where to pursue his higher education and what subjects they should be. Strassmann began his formal chemistry studies in 1920 at the Technical University of Hannover, supporting himself financially by working as a tutor for other students. He received a diploma in chemical engineering in 1924, and his PhD in physical chemistry in 1929. His doctoral research was on the solubility and reactivity of iodine in carbonic acid in the gas phase, and also enabled him to become experienced in analytical chemistry. Strassmann's doctoral advisor was Professor Hermann Braune. Subsequently, Strassmann received a partial scholarship to the Kaiser Wilhelm Institute for Chemistry in Berlin-Dahlem, beginning in 1929. There he studied radiochemistry with Otto Hahn, who arranged twice for his scholarship to be renewed. When his scholarship expired in September 1932, Strassmann continued to work as a research student in Hahn's laboratory, without a stipend but also without having to pay tuition. On 20 July 1937 Strassmann married Maria Heckter who was also a chemist. Strassmann was a self-taught violinist. He met Maria Heckter Strassmann through a group of young musicians that they both belonged to. The couple had a son, Martin. Maria Strassmann died of cancer in 1956. In 1959, Strassmann married journalist Irmgard Hartmann. He had known Hartmann for many years, as she was also a member of the same group of young musicians that Strassmann and his wife Maria had belonged to. Activities during Nazi rule In 1933 Strassmann resigned from the Society of German Chemists when it became part of a Nazi-controlled public corporation. He was blacklisted by