otto hahn - encycloipedia

Otto Hahn

Born 8 March 1879

Frankfurt am Main,

Hesse-Nassau, Prussia,

German Empire

Died 28 July 1968 (aged 89)

Göttingen, West Germany

Nationality German

Fields Radiochemistry

Nuclear chemistry

Alma mater University of Marburg

Doctoral

advisor

Theodor Zincke

Other academic

advisors

Adolf von Baeyer, University of

Munich;

Sir William Ramsay, University

College London;

Ernest Rutherford, McGill University

Montreal;

Emil Fischer, University of Berlin

Doctoral

students

Roland Lindner

Walter Seelmann-Eggebert

Johannes Heidenhain

Otto HahnFrom Wikipedia, the free encyclopedia

Otto Hahn, OBE, ForMemRS[1] (8 March 1879 – 28 July1968) was a German chemist and pioneer in the fields ofradioactivity and radiochemistry who won the NobelPrize in Chemistry in 1944 for the discovery and the

radiochemical proof of nuclear fission.[2] He is regardedas one of the most significant chemists of all time, and,

especially as "the father of nuclear chemistry".[3]

Hahn was an opponent of Jewish persecution by the Nazi

Party and, after World War II,[4] he became a passionatecampaigner against the use of nuclear energy as aweapon. He served as the last President of the KaiserWilhelm Society (KWG) in 1946 and as the foundingPresident of the Max Planck Society (MPG) from 1948 to1960. Considered by many to be a model for scholarly

excellence and personal integrity,[4] he became one of themost influential and respected citizens of the new FederalRepublic of Germany.

Contents

1 Early life2 Research in London and Montreal (1904–1906)

2.1 Discovery of radiothorium and other'new elements'

3 Research in Berlin (1906–1944)3.1 Discovery of mesothorium I (Ra 228)3.2 Discovery of radioactive recoil3.3 Marriage with Edith Junghans3.4 Discovery of protactinium3.5 Discovery of nuclear isomerism

4 Applied radiochemistry5 Discovery of nuclear fission (1938)6 Internment in England (1945)7 The Nobel Prize in Chemistry 19448 Founder and President of the Max PlanckSociety9 Spokesman for social responsibility10 Honors and awards11 Legacy12 Publications in English13 See also

Otto Hahn - Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Otto_Hahn

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Jan de Vries

Truus de Vries-Kruyt

Aristid von Grosse

Boris Nikitin

Laszlo Imre

Clara Lieber

Fritz Strassmann

Salomon Aminyu Rosenblum

Karl Erik Zimen

Hans-Joachim Born

Boris Sagortschew

Hans Götte

Siegfried Flügge

Nikolaus Riehl

Known for Discovery of radioactive elements

(1905–1921)

Radiothorium (1905)

Radioactinium (1906)

Mesothorium (1907)

Ionium (1907)

Radioactive recoil (1909)

Fajans–Paneth–Hahn Law

Protactinium (1917)

Nuclear isomerism (1921)

Applied Radiochemistry (1936)

Rubidium-strontium dating (1938)

Nuclear fission (1938)

Influenced Frédéric Joliot-Curie

Enrico Fermi

Glenn T. Seaborg

Edwin McMillan

Albert Ghiorso

Emilio Segrè

Philip Abelson

Joseph W. Kennedy

Nikolay Semyonov

Igor Kurchatov

Georgy Flyorov

Isaak Kikoin

Yulii Borisovich Khariton

Notable awards Emil Fischer Medal (1919)

Cannizzaro Prize (1939)

Copernicus Prize (1941)

14 References15 Bibliography16 External links

Early life

Hahn was the youngest son of Heinrich Hahn(1845–1922), a prosperous glazier and entrepreneur("Glasbau Hahn"), and Charlotte Hahn, née Giese(1845–1905). Together with his brothers Karl, Heiner andJulius, Otto was raised in a sheltered environment. At theage of 15, he began to take a special interest in chemistry,and carried out simple experiments in the laundry roomof the family home. His father wanted Otto to studyarchitecture, as he had built or acquired severalresidential and business properties, but Otto persuadedhim that his ambition was to become an industrialchemist.

In 1897, after taking his Abitur at the KlingerOberrealschule in Frankfurt, Hahn began to studychemistry and mineralogy at the University of Marburg.His subsidiary subjects were physics and philosophy.Hahn joined the Students' Association of NaturalSciences and Medicine, a student fraternity and aforerunner of today's "Landsmannschaft Nibelungia"(Coburger Convent der akademischenLandsmannschaften und Turnerschaften). He spent histhird and fourth semester studying under Adolf vonBaeyer at the University of Munich. In 1901, Hahnreceived his doctorate in Marburg for a dissertationentitled On Bromine Derivates of Isoeugenol, a topic inclassical organic chemistry. After completing his one yearmilitary service, the young chemist returned to theUniversity of Marburg, where for two years he worked asassistant to his doctoral supervisor, Geheimrat ProfessorTheodor Zincke.

Research in London and Montreal(1904–1906)

Discovery of radiothorium and other 'newelements'

Hahn's intention had been to work in industry. With thisin mind, and also to improve his knowledge of English,


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Nobel Prize in Chemistry (1944)

Max Planck Medal (1949)

Paracelsus Medal (1952)

Henri Becquerel Medal (1952)

Pour le Mérite (1952)

Faraday Lectureship Prize (1956)

ForMemRS (1957)[1]

Wilhelm Exner Medal (1958)

Hugo Grotius Medal (1958)

Légion d'Honneur (1959)

Enrico Fermi Award (1966)

Spouse Edith Junghans (1913–1968)

Signature

Sir William Ramsay, London

1905

Ernest Rutherford at McGill

University, Montreal 1905

he took up a post atUniversity CollegeLondon in 1904,working under SirWilliam Ramsay,known for havingdiscovered the inertgases. Here Hahnworked onradiochemistry, atthat time a very newfield. In early 1905,in the course of hiswork with salts ofradium, Hahndiscovered a newsubstance he calledradiothorium(thorium-228), whichat that time wasbelieved to be a new radioactive element. (In fact, it was a still undiscoveredisotope of the known element thorium. The term isotope was only coined in1913, by the British chemist Frederick Soddy).

Ramsay was very enthused when yet another new element was found in hisinstitute, and he intended to announce the discovery in a correspondinglysuitable way. In accordance with tradition this should be done before thecommittee of the venerable Royal Society. At the session of the RoyalSociety on the 16 March 1905 Ramsay communicated Hahn's discovery of

radiothorium,[5] and even the press was interested. The Daily Telegraph

informed its readers:[6]

"A NEW ELEMENT - Very soon the scientific papers will be agog with a new discovery which hasbeen added to the many brilliant triumphs of Gower Street. Dr. Otto Hahn, who is working atUniversity College, has discovered a new radioactive element, extracted from a mineral fromCeylon, named Thorianite, and possibly, it is conjectured, the substance which renders thoriumradioactive. Its activity is at least 250,000 times as great as that of thorium, weight for weight. Itgives off a gas (generally called an emanation), identical with the radioactive emanation fromthorium. Another theory of deep interest is that it is the possible source of a radioactive elementpossibly stronger in radioactivity than radium itself, and capable of producing all the curiouseffects which are known of radium up to the present. - The discoverer read a paper on the subjectto the Royal Society last week, and this should rank, when published, among the most original ofrecent contributions to scientific literature."

For the first time the name of Otto Hahn was mentioned in connection with radium research, and his "Newradioactive Element, which evolves Thorium Emanation" (so the original title) was published in the Proceedingsof the Royal Society in the issue of 24 March 1905 (76 A, pages 115-117). It was the first of more than 250scientific publications of Otto Hahn in the field of radiochemistry.


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"Hahn is a capital fellow and has done his work admirably. I am sure that you would enjoy havinghim to work with you."

wrote Ramsay to Ernest Rutherford in May 1905.[7]

Rutherford agreed and, from September 1905 until mid-1906, Hahn worked in his team at McGill University inMontreal, Canada where he discovered thorium C (later identified as polonium-212), radium D (later identifiedas lead-210), and radioactinium (later identified as thorium-227), and investigated the alpha rays of

radiothorium,[8] while Rutherford used to say in these days: "Hahn has a special nose for discovering new

elements."[9]

In his Rutherford biography the BBC Science Correspondent David Wilson analysed:[10]

"Greatest of all Rutherford's McGill collaborators was Otto Hahn, who became the world's leadingradio-chemist, a Nobel Prize winner, a man whose experiments showed the natural fission ofuranium, the crucial piece of work which opened the door to the atomic age in 1939."

Research in Berlin (1906–1944)

Discovery of mesothorium I (Ra 228)

In 1906, Hahn returned to Germany, where he collaborated with Emil Fischer at the University of Berlin. Fischerplaced at his disposal a former woodworking shop ("Holzwerkstatt") in the Chemical Institute to use as his ownlaboratory. There, in the space of a few months, using extremely primitive apparatus, Hahn discoveredmesothorium I, mesothorium II, and – independently from Bertram Boltwood – the mother substance of radium,ionium (later identified as thorium-230). In subsequent years, mesothorium I (radium-228) assumed greatimportance because, like radium-226 (discovered by Pierre and Marie Curie), it was ideally suited for use inmedical radiation treatment, while costing only half as much to manufacture.

"Hahn was rapidly carving out his place as the world's leading radio-chemist, with a series of newdiscoveries of radioactive daughter elements. He also showed a wisdom and humour whichimpressed Rutherford, for when the New Zealander suggested "paradium" as the name for one ofHahn's newly discovered elements - meaning "parallel to radium" - Hahn rejected the suggestion onthe grounds that the name was too reminiscent of military activity and goose-stepping."

wrote BBC's David Wilson in his Rutherford biography.[11]

In 1914, for the discovery of mesothorium I (radium-228), Otto Hahn was first nominated for the Nobel Prize inChemistry by Adolf von Baeyer and, in June 1907, by means of the traditional habilitation thesis, Hahnqualified to teach at the University of Berlin. On 28 September 1907 he made the acquaintance of the Austrianphysicist Lise Meitner who was almost the same age, who had transferred from Vienna to Berlin. So began thethirty-year collaboration and lifelong close friendship between the two scientists.

Discovery of radioactive recoil


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Marble plaque in Latin by Professor

Massimo Ragnolini, commemorating

the honeymoon of Otto Hahn and his

wife Edith at Punta San Vigilio, Lake

Garda, Italy, in March and April

1913. (Unveiled by Count Guglielmo

Guarienti di Brenzone in 1983).

After the physicist Harriet Brooks had observed a radioactive recoil in 1904, but interpreted it wrongly, OttoHahn succeeded, in late 1908 and early 1909, in demonstrating the radioactive recoil incident to alpha particleemission and interpreting it correctly.

"...a profoundly significant discovery in physics with far-reaching consequences",

as the physicist Walther Gerlach put it.[12] And Ernest Rutherford in Manchester wrote in a letter to his mother:

"He is doing the best work in Germany at present."[13]

In 1910 Hahn was appointed professor by the Prussian Minister of Culture and Education August von Trott zuSolz and, in 1912, he became head of the Radioactivity Department of the newly founded Kaiser WilhelmInstitute for Chemistry in Berlin-Dahlem (today 'Hahn-Meitner-Building' of the Free University, Berlin,Thielallee 63). Succeeding Alfred Stock, Hahn was director of the institute from 1928 to 1946. In 1924, Hahnwas elected to full membership of the Prussian Academy of Sciences in Berlin (proposed by Albert Einstein,Max Planck, Fritz Haber, Wilhelm Schlenk, and Max von Laue).

Marriage with Edith Junghans

In June 1911, while attending a conference in Stettin (today Szczecin,Poland) Otto Hahn met the young Edith Junghans (1887–1968), an artstudent at the "Königliche Kunstschule" (Royal Academy of Art) inBerlin. On 22 March 1913 the couple married in Edith's native city ofStettin, where her father, Paul Ferdinand Junghans, was a high-rankinglaw officer and President of the City Parliament until his 1915 death.Their only child, Hanno, born in 1922, became a distinguished arthistorian and architectural researcher (at the Hertziana in Rome), knownfor his discoveries in the early Cistercian architecture of the 12th century.In August 1960, while on a study trip in France, Dr Hanno Hahn wasinvolved in a fatal car accident, together with his wife and assistant IlseHahn, née Pletz. They left a fourteen-year-old son, Dietrich. In 1990, theHanno and Ilse Hahn Prize for outstanding contributions to Italian arthistory was established in memory of Hanno and Ilse Hahn to supportyoung and talented art historians. It is awarded biennially by theBibliotheca Hertziana – Max Planck Institute of Art History in Rome.

Discovery of protactinium

During the First World War, Hahn was conscripted into the army, where he was assigned, together with JamesFranck and Gustav Hertz, to the special unit for chemical warfare under the direction of Fritz Haber. The unitdeveloped, tested, and produced poison gas for military purposes, and was sent to both the western and easternfront lines. In December 1916, Hahn was transferred to the "Headquarters of His Majesty" in Berlin, and wasable to resume his radiochemical research in his institute. In 1917-1918, Hahn and Lise Meitner isolated along-lived activity, which they named "proto-actinium". Already in 1913, Kazimierz Fajans and Göhring had

isolated a short-lived activity from uranium X2 (later known as 234mPa), and called the substance "brevium".The two activities were different isotopes of the same undiscovered element number 91. For their discoveryHahn and Meitner were repeatedly nominated for the Chemistry-Nobel Prize in the 1920s by a number ofscientists, among them Max Bergmann, Viktor Moritz Goldschmidt, and even Kazimierz Fajans himself. In1949, the International Union of Pure and Applied Chemistry (IUPAC) named the new element definitely


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Hahn and Meitner, 1913, in the

chemical laboratory of the KWI.

protactinium, and confirmed Hahn and Meitner as discoverers.

Discovery of nuclear isomerism

In February 1921, Otto Hahn published the first report on his discovery

of uranium Z (later known as 234Pa ),[14] the first example of nuclearisomerism.

"...a discovery that was not understood at the time but laterbecame highly significant for nuclear physics",

as Walther Gerlach remarked.[12] And, indeed, it was not until 1936 thatthe young physicist Carl Friedrich von Weizsäcker succeeded inproviding a theoretical explanation of the phenomenon of nuclearisomerism. For this discovery, whose full significance was recognized byvery few, Hahn was again proposed, from 1923 till 1929, for the NobelPrize in Chemistry by Naunyn, Goldschmidt, and Max Planck.

Applied radiochemistry

In the early 1920s, Otto Hahn created a new field of work. Using the "emanation method", which he hadrecently developed, and the "emanation ability", he founded what became known as "Applied radiochemistry"for the researching of general chemical and physical-chemical questions. In 1936 he published a book in English(and later in Russian) entitled Applied Radiochemistry, which contained the lectures given by Hahn when he wasa visiting professor at Cornell University in Ithaca, New York in 1933. This important publication had a majorinfluence on almost all nuclear chemists and physicists in the United States, the United Kingdom, France, andthe Soviet Union during the 1930s and 1940s.

In 1966, Glenn T. Seaborg, co-discoverer of many transuranium elements and President of the United States

Atomic Energy Commission, wrote about this book as follows:[15]

"As a young graduate student at the University of California at Berkeley in the mid-1930s and inconnection with our work with plutonium a few years later, I used his book "AppliedRadiochemistry" as my bible. This book was based on a series of lectures which Professor Hahnhad given at Cornell in 1933; it set forth the "laws" for the co-precipitation of minute quantities ofradioactive materials when insoluble substances were precipitated from aqueous solutions. I recallreading and rereading every word in these laws of co-precipitation many times, attempting to deriveevery possible bit of guidance for our work, and perhaps in my zealousness reading into them morethan the master himself had intended. I doubt that I have read sections in any other book morecarefully or more frequently than those in Hahn's "Applied Radiochemistry". In fact, I read theentire volume repeatedly and I recall that my chief disappointment with it was its length. It was tooshort."

And Seaborg added:


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Otto Hahn, 1938

"It has been given to very few men to make contributions to science and to humanity of themagnitude of those made by Otto Hahn. He has made those contributions over a span of nearly twogenerations, beginning with a key role in the earliest days of radiochemistry in investigating andunraveling the complexities of the natural radioactivities and culminating with his tremendousdiscovery of the nuclear fission of uranium. I believe that it is fair to refer to Otto Hahn as thefather of radiochemistry and of its more recent offspring nuclear chemistry. For his special geniusthe world of science will be forever grateful."

Discovery of nuclear fission (1938)

Jointly with Lise Meitner and his pupil and assistant Fritz Strassmann(1902–1980), Otto Hahn furthered the research begun by Enrico Fermiand his team in 1934 when they bombarded uranium with neutrons. Until1938, it was believed that the elements with atomic numbers greater than92 (known as transuranium elements) arose when uranium atoms werebombarded with neutrons. The German chemist Ida Noddack proposedan exception. She anticipated the paradigm shift of 1938/39 in her articlepublished in the journal Angewandte Chemie, Nr. 47, 1934, in which shespeculated:

"It is conceivable that when heavy nuclei are bombarded withneutrons these nuclei could break down into several fairly largefragments, which are certainly isotopes of known elements, but notneighbors of the irradiated elements."

But no physicist or chemist really took Noddack's speculation seriouslyor tested it, not even Ida Noddack herself. The idea that heavy atomicnuclei could break down into lighter elements was regarded as totallyinadmissible.

Between 1934 and 1938, Hahn, Meitner, and Strassmann found a great number of radioactive transmutation

products, all of which they regarded as transuranic.[16] At that time the existence of actinides was not yetestablished, and uranium was wrongly believed to be a group 6 element similar to tungsten. It followed that firsttransuranic elements would be similar to group 7 to 10 elements, i.e. rhenium and platinoids. The Hahn groupestablished the presence of multiple isotopes of at least four such elements, and (mistakenly) identify them as

elements with atomic numbers 93 through 96. They were the first scientists to measure the half-life of 239U andto establish chemically that it was an isotope of uranium, but they were unable to continue this work to its

logical conclusion and identify the decay product of 239U – namely, neptunium (the real element 93); this taskwas only completed by Edwin McMillan and Philip H. Abelson in 1940.

On 13 July 1938, with the help and support of Hahn, Lise Meitner – born into a Jewish family – escaped to the

Netherlands;[17] before she left, Hahn gave her a diamond ring he had inherited from his mother, to be used tobribe the frontier guards if required. Meitner emigrated to Stockholm, and Hahn continued to work withStrassmann. In late 1938 they found evidence of isotopes of an alkaline earth metal in their sample. The metalwas detected by the use of an organic barium salt constructed by Wilhelm Traube. Finding a group 2 alkalineearth metal was problematic, because it did not logically fit with the other elements found thus far. Hahn initiallysuspected it to be radium, produced by splitting off two alpha-particles from the uranium nucleus. At the time,


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Nuclear fission experimental setup,

reconstructed at the Deutsches

Museum, Munich.

Otto Hahn's notebook

Plaque commemorating the discovery

of fission in Berlin (unveiled 1956)

the scientific consensus was that even splitting off two alpha particles viathis process was unlikely. The idea of turning uranium into barium (byremoving around 100 nucleons) was seen as preposterous. On 10November during a visit to Copenhagen, where he was invited to lecturein Bohr's Institute, Hahn discussed these results with Niels Bohr, Lise

Meitner, and Otto Robert Frisch.[17] Further refinements of thetechnique, leading to the decisive experiment on 16–17 December 1938(the celebrated "radium-barium-mesothorium-fractionation"), producedpuzzling results: the three isotopes consistently behaved not as radium,but as barium. Hahn, who did not inform the physicists in his Institute,described the results exclusively in a letter to Meitner on 19 December:"...we are more and more coming to the awful conclusion that our Raisotopes behave not like Ra, but like Ba. ... Perhaps you can suggestsome fantastic explanation. We ourselves realize that it can't really burst

into Ba."[18] In her reply, Meitner concurred that Hahn's conclusion ofthe bursting of the uranium nucleus was very difficult to accept, butconsidered it possible.

On 22 December 1938, Hahn sent a manuscript to Naturwissenschaftenreporting their radiochemical results, which were published on 6 January

1939.[19] On 27 December, Hahn telephoned the editor ofNaturwissenschaften and requested to add a paragraph to the article,speculating that some platinum group elements previously observed inirradiated uranium, which were originally interpreted as transuraniumelements, could in fact be technetium (then called "masurium") andlower platinum-group metals (atomic numbers 43 through 46). ByJanuary 1939 he was sufficiently convinced that formation of lightelements was occurring in his setup that he published a new revision ofthe article, essentially retracting former claims of observing transuranicelements and neighbors of uranium, and concluding instead that he wasseeing light platinoids, barium, lanthanum, and cerium.

Fritz Strassmann recollects:[20]

"The significance accorded to the outcome from thescientific point of view becomes clear when one reads in thefirst publication of nuclear fission that Professor Hahn, whohad over 30 years of practical and theoretical experience inthe sphere of radioactivity and whose judgementunquestionably commanded the greatest weight amongfellow scientists both in Germany and the whole world,announced the new discovery only hesitatingly. Theradiochemical methods he applied, which were partlydeveloped by him, tested out hundreds of times in the courseof 30 years and found to be reliable, did not permit anydoubt about the finding."

As a chemist, Hahn was reluctant to propose a revolutionary discovery in physics,[16] but Lise Meitner and her


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nephew, the young physicist Otto Robert Frisch, in Sweden, came to the same conclusion (a bursting) as Hahnand were able, because they had a lead of time, to work out the first theoretical interpretation of nuclear fission –the term that was coined by Frisch, and which subsequently became internationally known. Over the next fewmonths, Frisch and Meitner published two articles discussing and experimentally confirming this hypothesis.[21][22]

In a later appreciation (1963), Lise Meitner wrote:[4]

"The discovery of nuclear fission by Otto Hahn and Fritz Strassmann opened up a new era inhuman history. It seems to me that what makes the science behind this discovery so remarkable isthat it was achieved by purely chemical means."

And in an interview on West German television (ARD, 8 March 1959), Meitner said:[4]

"Hahn and Strassmann were able to do this by exceptionally good chemistry, fantastically goodchemistry, which was way ahead of what anyone else was capable of at that time. The Americanslearned to do it later. But at that time, Hahn and Strassmann were really the only ones who could doit. And that was because they were such good chemists. Somehow they really succeeded in usingchemistry to demonstrate and prove a physical process."

In the same interview Fritz Strassmann responded with this clarification:[4]

"Professor Meitner stated that the success could be attributed to chemistry. I have to make a slightcorrection. Chemistry merely isolated the individual substances, it did not precisely identify them. Ittook Professor Hahn's method to do this. This is where his achievement lies."

And James Chadwick wrote in a preface:[23]

"This exciting discovery of the 'bursting' or 'fission' of uranium owed, to my mind, as much to thecharacter of Hahn as to his great competence as a radiochemist. In all his scientific work one seeshis untiring determination to get to the bottom of his problems, his refusal to be satisfied with lessthan as complete a knowledge as possible of the facts, followed by his acceptance of these facts,however unexspected they might be. [...] This discovery was the crowning achievement of more thanthirty years of research in the subject of radioactivity, during which his many outstandingcontributions had already brought him a high reputation."

In their second publication on nuclear fission (Die Naturwissenschaften, 10 February 1939) Otto Hahn and FritzStrassmann used for the first time the term Uranspaltung (uranium fission), and predicted the existence andliberation of additional neutrons during the fission process, which was proved to be a chain reaction by FrédéricJoliot and his team in March 1939.

Rudolf Ladenburg, émigré physicist at Princeton University (Palmer Laboratory) wrote to Hahn on February 22,

1939:[24]


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Otto Hahn, Farm Hall,

1945

Hiroshima after the bombing on

August 6, 1945

The bomb over Nagasaki on August

9, 1945

"Your discovery has caused a huge sensation in the whole scientific world, and every laboratorywhich has the necessary means is now working on the consequences of your discovery."

During the war, Otto Hahn – together with his assistants Hans-Joachim Born, Siegfried Flügge, Hans Götte,Walter Seelmann-Eggebert, and Fritz Strassmann – worked on uranium fission reactions. By 1945 he had drawnup a list of 25 elements and about 100 isotopes whose existence he had demonstrated.

Internment in England (1945)

At the end of World War II in 1945 Hahnwas suspected of working on the Germannuclear energy project to develop an atomicreactor or an atomic bomb, but his onlyconnection was the discovery of fission; hedid not work on the program. In April 1945,Hahn and nine leading German physicists(including Max von Laue, WernerHeisenberg, and Carl Friedrich vonWeizsäcker) were taken into custody by theAlsos Mission (see Operation Epsilon) andinterned at Farm Hall, Godmanchester, nearCambridge, England, from 3 July 1945 to 3January 1946. The chief officer, MajorTerence H. Rittner informed the authoritiesabout his prisoners. He described Hahn asfollows:

"A man of the world. He has been the most helpful of theprofessors and his sense of humour and common sense hassaved the day on many occasions. He is definitely friendly

disposed to England and America."[25]

In Farm Hall the German scientists learned of the dropping of the atombombs on Hiroshima and Nagasaki by the American airforce on 6 and 9August 1945. Otto Hahn was on the brink of despair.

The historian Lawrence Badash (from the University of California at

Santa Barbara) wrote in his essay:[26]

"Hahn had been the first informed about Hiroshima onAugust 6, 1945, by the British officer in charge at FarmHall. The news completely shattered him, for he felt thathis discovery of fission had made construction of theatomic bomb possible, and that he was thus personallyresponsible for the thousands of deaths in Japan. Longbefore, he had contemplated suicide, when he first


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recognized the possible military use of fission; now, with the blame of its realization drawnsquarely upon his shoulders, suicide again seemed a way to escape his desolation. Fearing this,Max von Laue remained with him until he passed this personal crisis. Never has socialresponsibility hit a scientist with such impact."

On January 3, 1946, the group was allowed to return to Germany, and Hahn, Heisenberg, and von Laue werebrought to the city of Göttingen, which was controlled by the British occupation authorities.

The Nobel Prize in Chemistry 1944

On 15 November 1945 the Royal Swedish Academy of Sciences announced that Hahn had been awarded the

1944 Nobel Prize in Chemistry "for his discovery of the fission of heavy atomic nuclei."[2][27][28] SomeUS-American historians have documented their view of the discovery of nuclear fission and believe Meitner

should have been awarded the Nobel Prize with Hahn.[29][30][31] Hahn was still being detained at Farm Hallwhen the announcement was made; thus, his whereabouts were a secret, and it was impossible for the Nobelcommittee to send him a congratulatory telegram. Instead, he learned about his award through the Daily

Telegraph newspaper.[32] His fellow interned German scientists celebrated his award on 18 November by giving

speeches, making jokes, and composing songs.[33] On 4 December, Hahn was persuaded by two of his captors towrite a letter to the Nobel committee accepting the prize but also stating that he would not be able to attend the

award ceremony.[34] He could not participate in the Nobel festivities on 10 December since his captors wouldnot allow him to leave Farm Hall.

"Surely Hahn fully deserved the Nobel Prize in chemistry. There is really no doubt about it. But Ibelieve that Otto Robert Frisch and I contributed something not insignificant to the clarification ofthe process of uranium fission – how it originates and that it produces so much energy, and that wassomething very remote from Hahn."

wrote Lise Meitner to her friend B. Broomé-Aminoff on November 20, 1945.[35] And Meitner's former assistantCarl Friedrich von Weizsäcker later added:

"He certainly did deserve this Nobel Prize. He would have deserved it even if he had not made thisdiscovery. But everyone recognized that the splitting of the atomic nucleus merited a Nobel

Prize."[4]

The radiochemist and Jewish émigré Elizabeth Rona (later a Professor of Chemistry in Miami) wrote in her

memoirs:[36]

"I often thought, that he would have deserved a second Nobel Prize - the Nobel Prize for peace."

Hahn attended the Nobel festivities the year after he was awarded the prize. On 10 December 1946, King Gustav

V of Sweden presented him with his Nobel Prize medal and diploma.[28]

The chemist and science historian Klaus Hoffmann wrote in his biography (translated by J. Michael Cole,


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Otto Hahn stamp, Germany 1979.

Leyburn, UK):[37]

"Uranium fission is exclusively chemical, and had not beenproved physically, and, to be precise, had been demonstratedby Otto Hahn and Fritz Strassmann alone. Lise Meitner hadrepeatedly conceded and emphasised the recognition of theachievement of these two, and that the chemical proof of thephysics effect of uranium fission could have been carried outby no other research team in the world in 1938. [...] In theradiochemical analytical work in the second half of the yearof 1938, which immediately led to the proof of the fission ofthe nucleus, the absent Lise Meitner had no part at all.

Doubtless Meitner and Frisch, but not Hahn's ladycolleague alone, had merit in the interpretation of the resultsobtained by Hahn and Strassmann with regard to thephysical character of the nuclear fission. But they did notgain these laurels, because in January 1939 they were theonly ones in the world who were qualified in that area.Rather was it through the unqualified revelation by Hahn ofhis results that they had a lead in time over others. As thesubsequent events confirmed, they arrived at the sameresults. [...]

Once again - the Nobel Prize for Chemistry of 1944 wasawarded for the fission of the atomic nucleus of uranium, adiscovery which no physicist, including Lise Meitner, haddeliberately investigated, because it had not been held to bepossible. - The reproaches against Hahn that he alone hadbeen nominated for the Nobel Prize and that he alone hadreceived it are just as mistaken - as if Hahn could have doneanything about this decoration finally becoming a reality,after he had been nominated for it for over twenty years.[...] - But of course the Nobel Committee took into accountin its decision that Hahn had many times been in the arenaas a candidate for the Nobel Prize because of hisperformance beforehand, whereas Strassmann had not beenat all."

Otto Hahn had been nominated 22 times for the Nobel Prize in Chemistry from 1914 to 1945, and 16 times for

the Nobel Prize in Physics from 1937 to 1947.[38]

In 1951 Samuel C. Lind, the eminent American radiation scientist from the University of Minnesota inMinneapolis, wrote in a review:

"No living man has so successfully spanned the world of discovery from radiothorium to fission, one

of the greatest - if not the greatest - discovery of all time."[39]


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Monument in Berlin-Dahlem, in front

of the Otto-Hahn-Platz

Founder and President of the Max Planck Society

From 1948 to 1960 Otto Hahn was the founding President of the newlyformed Max Planck Society for the Advancement of Science, whichthrough his tireless activity and his worldwide respected personalitysucceeded in regaining the renown once enjoyed by the Kaiser WilhelmSociety.

Lawrence Badash wrote:

"Hahn learned while still interned at Farm Hall that he wasawarded the Nobel Prize in chemistry for the discovery offission. This added prominence to his already distinguishedcareer, and his wartime anti-Nazi stance made him all themore acceptable to the Allied occupation authorities. Thus,he became the leading figure in the resurrection of Germanscience after the war, an elder statesman who held theconfidence of the various factions. In his position aspresident, he was particularly successful in rebuilding theKaiser Wilhelm Society, the parent body of the institutes,

which was renamed the Max Planck Society."[26]

And Sir James Chadwick noted:

"Hahn had accepted this onerous office with muchmisgiving. He was, however, a happy choice; not so muchbecause of his political record or his scientific eminence, butbecause of his character - he had an honesty and integritywhich commanded the respect and trust of all. He took theleading part in the re-establishment of science in WestGermany and, when he retired from his office in 1960, hecould look back with pride on a remarkable

achievement."[40]

Spokesman for social responsibility

Immediately after the Second World War, Hahn reacted to the dropping of the atomic bombs on Hiroshima andNagasaki by coming out strongly against the use of nuclear energy for military purposes. He saw the applicationof his scientific discoveries to such ends as a misuse, or even a crime.

"His wartime recognition of the perversion of science for the construction of weapons and hispostwar activity in planning the direction of his country's scientific endeavours now inclined him

increasingly toward being a spokesman for social responsibility."[41]


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In early 1954 he wrote an article "Cobalt 60 - Danger or Blessing for Mankind?" about the misuse of atomicenergy, which was widely reprinted and transmitted in the radio in Germany, Norway, Austria, and Denmark,and in an English version worldwide via the BBC. The international reaction was encouraging.

The next year Hahn initiated and organized the Mainau Declaration of 1955, in which he and a number ofinternational Nobel Prize-winners called attention to the dangers of atomic weapons and warned the nations ofthe world urgently against the use of "force as a final resort", and which was issued a week after the similarRussell-Einstein Manifesto. In 1956 Hahn repeated his appeal with the signature of 52 of his Nobel colleaguesfrom all parts of the world.

He was also instrumental in and one of the authors of the Göttingen Manifesto of April 13, 1957, in which,together with 17 leading German atomic scientists, he protested against a proposed nuclear arming of the newWest German armed forces (Bundeswehr).

On November 13, 1957, in the 'Konzerthaus' (Concerto Hall) in Vienna, Hahn warned in his Vienna Appeal ofthe "dangers of A- and H-bomb-experiments", and declared that "today war is no means of politics anymore - itwill only destroy all countries in the world". His highly acclaimed speech was transmitted internationally by theAustrian radio, Österreichischer Rundfunk (ÖR). On December 28, 1957, Hahn repeated his appeal in an

English translation for the Bulgarian Radio in Sofia, which was broadcast in all Warsaw pact states.[42]

In January 1958, Otto Hahn, together with his friend Albert Schweitzer signed the Pauling Appeal to the UnitedNations in New York for the "immediate conclusion of an international agreement to stop the testing of nuclearweapons" and, in October, together with Clement Attlee, Edgar Faure, Tetsu Katayama, et al. he signed theinternational "Agreement to call a meeting to draw up a world constitution".

Since 1958 Hahn was sending messages to the annual conferences of the recently founded "Japan CouncilAgainst A and H Bombs" in Tokyo. In 1960, for instance, he wrote to president Koshiro Okakura:

"As I have often emphasized on official occasions and in my lectures, I consider the manufacturingof A and H bombs a great danger to mankind, especially when small countries, one after another,wish to produce them, too. It would be satisfactory if the USA and Britain on one hand and theSoviet Union on the other be neutralized by the possession of those bombs.

We must reach an agreement through negotiations with these 'A-bomb-manufacturing nations', andeven after that I am against any further increasing of A bombs and support all that is opposed to the

expansion of them. - I wish a full success to the Japan Council Against A and H Bombs."[43]

In 1959 Hahn co-founded in Berlin the Federation of German Scientists (VDW), a non-governmentalorganization, which has been committed to the ideal of responsible science. The members of the Federation feelcommitted to taking into consideration the possible military, political, and economical implications andpossibilities of atomic misuse when carrying out their scientific research and teaching. With the results of itsinterdisciplinary work the 'VDW' not only addresses the general public, but also the decision-makers at all levelsof politics and society.

Right up to his death, Otto Hahn never tired of warning urgently of the dangers of the nuclear arms race between

the great powers and of the radioactive contamination of the planet.[44]

The philosopher Sir Karl R. Popper wrote in his last book:


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Otto Hahn aboard the MS Düsseldorf,

June 1965

"Ever since my early youth, I have admired Otto Hahn as a scientist and a human being. The reasonfor Hahn's peace work was simply that, knowing more than other citizens about atomic weapons, hefelt it his duty to speak about this issue that was so crucial for mankind. He could make things clear,he had to use his knowledge. And it is why Otto Hahn, with atomic weapons in mind, wrote shortly

before his death of the necessity of world peace." [45]

The historian Lawrence Badash analysed:

"Otto Hahn is widely portrayed as a warm, considerate, charming person. The characterization isaccurate. In fact, precisely because the personality of this decent human being suffered no greatchanges throughout his career, he offers us a touchstone to determined the extent of changes inscientists' perceptions of their obligations to society during the twentieth century. [...]

The important thing is not that scientists may disagree on where their responsibility to society lies,but that they are conscious that a responsibility exists, are vocal about it, and when they speak outthey expect to affect policy. Otto Hahn, it would seem, was even more than just an example of this

twentieth-century conceptual evolution; he was a leader in the process." [46]

From 1957, Hahn was repeatedly nominated for the Nobel Peace Prize by a number of internationalorganizations, including the largest French trade union, the Confederation Generale du Travail (CGT). - Linus

Pauling, the 1962 Nobel Peace laureate, once described Otto Hahn as "an inspiration to me." [4]

Honors and awards

During his lifetime Hahn was awarded orders, medals, scientific prizes,and fellowships of Academies, Societies, and Institutions from all overthe world. A selection:

Iron Cross, 1st and 2nd class, German Empire (1915)General Honor Decoration (Hesse), German Empire (1916)Knight of the Royal House Order of Hohenzollern, Kingdom ofPrussia (1917)Officer of the Albert Order, Kingdom of Saxony (1917)

numerous honorary degrees and was elected member or honorarymember of 45 Academies and scientific societies (among them theUniversity of Cambridge, the Physical Society, the University

College and the Royal Society in London,[1] the Romanian Physical Society in Bucharest, the RoyalSpanish Society for Chemistry and Physics in Madrid, the CSIC in Madrid, and the Academies inAllahabad (India), Bangalore (India), Berlin, Boston (USA), Bucharest, Copenhagen, Göttingen, Halle,Helsinki, Lisbon, Madrid, Mainz, Munich, Rome, Stockholm, Vatican, and Vienna). Hahn was, too, anhonorary member of the German Physical Society (DPG), the Society of German Chemists (GDCh), andthe German Bunsen-Society of Physical Chemistry.

37 of the highest national and international orders and medals, among them the Gold Medals Emil Fischer,Cannizzaro, Copernicus, Henri Becquerel, Paracelsus, Fritz Haber, Marie Curie, Cothenius, Senckenberg,


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Hahn's grave in Göttingen

Theodor Goldschmidt, Heraeus, and Hugo Grotius, the MaxPlanck medal, the Faraday Lectureship Prize with Medal from theRoyal Society of Chemistry in London, the Exner-Medal inVienna, the Harnack medal in Gold from the Max Planck Society,and the Gold Medal of the Pontifical Academy of Sciences fromPope John XXIII in the Vatican.

Officer of the Order for Cultural Merit, Kingdom of Romania(1939)Knight of the Peace Class of the Order Pour le Mérite, FederalRepublic of Germany (1952)Grand Cross with star and sash of the Order of Merit of theFederal Republic of Germany (1954)Gold Cross of the Order of the Redeemer, Kingdom of Greece(1956)Elected a Foreign Member of the Royal Society (ForMemRS) in

1957[1]

Honorary Officer of the Order of the British Empire, UnitedKingdom (1957)Gold Cross of the Order Pro Ecclesia et Pontifice, Holy See (1957)Officer of the Order of Leopold, Kingdom of Belgium (1958)Officer of the 'Ordre National de la Légion d'Honneur', Republic of France (1959)Grand Cross First Class of the Order of Merit of the Federal Republic of Germany (1959)

In 1957 Hahn was elected an honorary citizen of the city of Magdeburg, DDR (German Democratic Republic)and, in 1958, an honorary member of the Academy of Sciences of the USSR (today Russian Academy ofSciences) in Moscow, but he declined both honors.

In 1966, President Lyndon B. Johnson of the USA and the United States Atomic Energy Commission (AEC) inWashington awarded Hahn (together with Lise Meitner and Fritz Strassmann) the Enrico Fermi Award (with agold medal and citation). The diploma for Hahn bears the words:

"For pioneering research in the naturally occurring radioactivities and extensive experimental

studies culminating in the discovery of fission.[47]

Hahn, since 1960 honorary president of the MPG, was made an honorary citizen of the cities of Frankfurt amMain and Göttingen in 1959, and of the land and the city of Berlin in 1968. The British physicist Robert SpenceFRS, concluded in his essay:

It was remarkable, how, after the war, this rather unassuming scientist who had spent a lifetime inthe laboratory, became an effective administrator and an important public figure in Germany.Hahn, famous as the discoverer of nuclear fission, was respected and trusted for his human

qualities, simplicity of manner, transparent honesty, common sense, and loyalty.[48]

Otto Hahn died on 28 July 1968. The day after his death the Max Planck Society published the following

obituary notice in all the major newspapers in Germany, Austria, and Switzerland:[49]


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Otto Hahn on a stamp of the German

Democratic Republic, 1979Hahn monument at the site of his

birthplace in Frankfurt

On 28 July, in his 90th year, our Honorary President Otto Hahn passed away. His name will berecorded in the history of humanity as the founder of the atomic age. In him Germany and the worldhave lost a scholar who was distinguished in equal measure by his integrity and personal humility.The Max Planck Society mourns its founder, who continued the tasks and traditions of the KaiserWilhelm Society after the war, and mourns also a good and much loved human being, who will livein the memories of all who had the chance to meet him. His work will continue. We remember himwith deep gratitude and admiration.

Fritz Strassmann, Hahn's pupil and assistant, wrote:[50]

The number of those who had been able to be near Otto Hahn is small. His behaviour wascompletely natural for him, but for the next generations he will serve as a model, regardless ofwhether one admires in the attitude of Otto Hahn his humane and scientific sense of responsibilityor his personal courage.

Otto Robert Frisch, Lise Meitner's nephew, recollected:[51]

Hahn remained modest and informal all his life. His disarming frankness, unfailing kindness, goodcommon sense, and impish humour will be remembered by his many friends all over the world.

And the Royal Society in London wrote in an obituary:[52]

Otto Hahn's achievements are known universally and will hold a special place in the history ofscience. He is remembered too for his whole character, his generosity of spirit, his belief in theproper use of scientific discovery, and for his humanity.

Legacy

Hahn's death did not stop hispublic acclamation. Proposalswere made at different times, firstin 1971 by American chemists,that the newly synthesizedelement no. 105 should be namedhahnium in Hahn's honor; in1997 the IUPAC (InternationalUnion of Pure and AppliedChemistry) named it dubnium,after the Russian research centerin Dubna (see element namingcontroversy). Although element 108 was given the name hassium by its

officially-recognized German discoverers in 1992, a 1994 IUPAC committee recommended that it be named

hahnium (Hn),[53] in spite of the long-standing convention to give the discoverer the right to suggest a name.


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5 Mark coin, honoring Otto Hahn and

his discovery of nuclear fission.

Federal Republic of Germany, 1979

Bust by Knud Knudsen

Caricature by Gheorghe Manu,

Romania

This recommendation was notadopted, following protests fromthe German discoverers, and thename hassium (Hs) was adopted

internationally in 1997.[54]

In 1964 the only Europeannuclear-powered civilian ship, thefreighter NS Otto Hahn, wasnamed in his honor. In 1959 therewere the opening ceremonies ofthe Otto Hahn Institute in Mainzand the Hahn-Meitner-Institut forNuclear Research (HMI) inBerlin. There are craters on Marsand the Moon, and the asteroids No. 3676 Hahn and No. 19126Ottohahn named in his honor, as were the Otto Hahn Prize of both theGerman Chemical and Physical Societies and the city of Frankfurt/Main,

the Otto Hahn Medal, and the Otto Hahn Award of the Max Planck Society and, since 1988, the Otto HahnPeace Medal in Gold of the United Nations Association of Germany (DGVN) in Berlin.

Many cities and districts in the German-speaking countries have namedsecondary schools after him, and streets, squares, and bridges throughoutEurope bear his name. More than twenty states worldwide have honoredOtto Hahn by issuing coins, medals or stamps with his portrait. An islandin the Antarctic (near Mt. Discovery) was also named after him, as weretwo Intercity trains Otto Hahn of the German Federal Railways in 1971,running between Hamburg and Basel SBB, and the Otto Hahn Library inGöttingen. In 1974, in appreciation of the special contribution of OttoHahn to German-Israeli relations, a wing of the Weizmann Institute ofScience in Rehovot, Israel, was given his name, and a scientific researchcenter of the Saint Louis University (Baguio) (Philippines) was namedthe Otto Hahn Building.

In several cities and districts Otto Hahn busts, monuments, and memorialplaques were unveiled, including in Vienna in the foyer of theInternational Atomic Energy Agency (IAEA). There are public OttoHahn Centers in Göttingen and Ottobrunn (near Munich), and planned inthe near future also in Hahn's native city Frankfurt/Main, while in 2011the city of Albstadt created an Otto Hahn Memorial place in her localIHK-Academy, focussed on Hahn's work in Tailfingen at the end ofWorld War II. In early 2014, the University of Dortmund opened two new Otto Hahn Libraries in her GeneralUniversity Library, which are specialized in the natural sciences and technologies.

At the end of 1999, the German news magazine Focus published an inquiry of 500 leading natural scientists,engineers, and physicians about the most important scientists of the 20th century. In this poll the experimentalchemist Otto Hahn – after the theoretical physicists Albert Einstein and Max Planck – was elected third (with 81

points), and thus the most significant empiric researcher of his time.[55]

Publications in English


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1936. Applied Radiochemistry. Cornell University Press, Ithaca, New York 1936. Humphrey Milford,London 1936. Oxford University Press, Oxford 1936.1950. New Atoms – Progress and some memories. Edited by W. Gaade. Elsevier Inc., NewYork-Amsterdam-London-Brussels.1966. A Scientific Autobiography. Introduction by Glenn T. Seaborg. Translated and edited by Willy Ley.Charles Scribner's Sons, New York. British edition: McGibbon and Kee, London 1967.1970. My Life. Preface by Sir James Chadwick. Translated by Ernst Kaiser and Eithne Wilkins.Macdonald & Co., London. American edition: Herder and Herder, New York 1970.


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otto hahn - encycloipedia

Documents

discovery of mesothorium

discovery of radiothorium

discovery of protactinium3

father of nuclear chemistry

alsootto hahn wikipedia

charlotte hahn

entrepreneurglasbau

use of nuclear energy