Otto Hahn

Biography

Otto Hahn (1879-1968) was a German chemist who changed the way we understand atomic structure with his pioneering work in radiochemistry. Born in Frankfurt on March 8, 1879, Hahn became known as the father of nuclear chemistry and discovered nuclear fission. These discoveries became the basis for both nuclear power and nuclear weapons. His career covered a turbulent period in European history, during which he made significant contributions to atomic science while dealing with the challenges of two world wars and their aftermath.

After earning his doctorate from the University of Marburg in 1901, Hahn broadened his scientific knowledge by studying internationally with well-known researchers Sir William Ramsay at University College London and Ernest Rutherford at McGill University in Montreal. During this time, he discovered several new radioactive isotopes, which established his reputation in the new field of radioactivity research. He returned to Germany in 1906, where Emil Fischer provided him lab space in the basement of the Chemical Institute at the University of Berlin. There, he completed his habilitation and became a Privatdozent in 1907.

Hahn's most successful scientific partnership began in 1912 when he became head of the Radioactivity Department at the newly established Kaiser Wilhelm Institute for Chemistry. Working alongside Austrian physicist Lise Meitner, he conducted systematic investigations of radioactive elements that led to remarkable results. Together, they discovered isotopes of radium, thorium, protactinium, and uranium, with Meitner isolating the longest-lived isotope of protactinium in 1918. Hahn also identified atomic recoil and nuclear isomerism, and he developed the rubidium-strontium dating method essential for geological and archaeological research.

The peak of Hahn's scientific career came in 1938 when he, Meitner, and Fritz Strassmann achieved nuclear fission through neutron bombardment experiments. They found that atomic nuclei could be split, releasing huge amounts of energy and significantly changing humanity's view of atomic power. For this work, Hahn received the 1944 Nobel Prize in Chemistry, although Meitner's exclusion from the prize remains controversial. His World War I military service, including work with Fritz Haber's chemical warfare unit, earned him the Iron Cross (2nd Class), while his later scientific achievements brought many international honors such as the Officer of the Order of the British Empire (1957) and the Officer of the Legion of Honour (1959). Hahn died in Göttingen on July 28, 1968, and his scientific work continues to impact nuclear physics and chemistry.