• Otto Hahn was born on March 8, 1879 at  Frankfurt-on-the-Main, Germany
  • Otto Hahn was awarded the Chemistry Nobel Prize "for his discovery of the fission of heavy nuclei". Otto Hahn is known as the Father of Nuclear Chemistry. The prize winning spectacular discovery came at the end of 1938, when Hahn was working on the processes of irradiating uranium and thorium with neutrons. The experiment led to the decay of uranium nucleus producing barium, a far too lighter element than uranium. This phenomenon, later called "fission", became the key step in developing nuclear weapons and energy.
  • In his teenage years, Hahn had developed a liking for chemistry and continued his study to obtain doctorate in organic chemistry in 1901. Then after a year of service in the German military, Hahn spent two years working as a laboratory assistant.
  • In 1904, he moved to University College, London to work under Sir William Ramsay (Nobel Prize winner for the discovery of noble gases), and this was the place where he became interested in radioactive elements. These are elements with unstable nuclei that generate radiation in the form of neutrons, protons, or energy as time goes on during radioactive decay. Here he discovered a new radioactive substance, radiothorium (an isotope of thorium).
  • During 1905-1906, Hahn discovered radioactinium and investigated on alpha-rays produced from of radiothorium and radioactinium (thorium-227) while working under Professor Ernest Rutherford at the Physical Institute of McGill University, Montreal, Canada.
  • In 1906 Hahn returned to Germany, to join as a university lecturer at the Chemical Institute of the University of Berlin. Here he discovered mesothorium-I (later identified as radium-228), which assumed great importance for use in medical radiation treatment. From 1907 onwards, his association with the physicist Lise Meitner was the beginning of their thirty years long collaboration, which resulted in the famous discovery of nuclear fission. Along with new radioactive elements, they also discovered radioactive recoil, a process where an atom goes the opposite direction of the particle or radiation it emits.
  • Hahn was against any application of his scientific discoveries toward weapon for mass destruction or misuse. He came out strongly criticizing the dropping of the atomic bombs on Hiroshima and Nagasaki during the Second World War.
  • Otto Hahn died on July 28, 1968 in Göttingen, Germany.  He is remembered as the founder of the atomic age and a scholar who is distinguished in equal measure by his integrity and personal humility.

Contributed by Dr Rohit Kumar Rana, CSIR-Indian Institute of Chemical Technology, Hyderabad