Frederick Soddy

For more information on Frederick Soddy, visit Britannica.com.

British chemist (1877–1956)

Soddy, born the son of a corn merchant in the coastal town of Eastbourne, was educated at the University College of Aberystwyth and Oxford University. After working with Ernest Rutherford in Canada and William Ramsay in London, Soddy took up an appointment at Glasgow University in 1904. He moved to take the chair of chemistry at Aberdeen University in 1914 where he remained until 1919 when he accepted the post of Dr. Lee's Professor of Chemistry at Oxford.

Soddy's work was quite revolutionary in that he succeeded in overthrowing two deep assumptions of traditional chemistry. The first arose out of his period of collaboration with Rutherford, from 1901 to 1903. Together they established that radioactive elements could change into other elements through a series of stages.

Soddy's next major achievement was to make some kind of sense of the bewildering variety of new elements that had been found as decay products of radium, thorium, and uranium. The books of the period refer to such strange entities as mesothorium, ionium, radium A, B, C, D, E, and F, and uranium X. Such entities were clearly distinct for they had markedly different half-lives. But what they were and, more significantly, where they fitted in the periodic table were difficult questions. There were gaps in the periodic table but far too few to accommodate so many new elements. One further difficulty soon forced itself on chemists. Attempts to separate thorium from radiothorium by Otto Hahn in 1905 and radium D from lead by Georg von Hevesy a few years later had failed, as had numerous other attempts to separate various radioactive elements by chemical means.

Finally Soddy made the bold claim that the reason such substances could not be separated was because they were in fact identical. Consequently some kind of modification of the periodic table was called for. In his view (1913) “it would not be surprising if the elements…were mixtures of several homogeneous elements of similar but not completely identical atomic weights.” He called such chemically identical elements, with slightly differing atomic weights, isotopes (from the Greek words meaning in the same place). He could thus assert that both radium D and thorium C were in fact isotopes of lead. Radium D has a half-life of 24 years and an atomic weight of 210 while thorium C has a half-life of 87 minutes and an atomic weight of 212; but, although they have different half-lives and slightly differing weights, they were both chemically indistinguishable as lead.

Until the discovery of the neutron by James Chadwick a complete understanding of this enormously fruitful idea was not available to Soddy. All he could propose, somewhat vaguely, as an explanation was different numbers of positive and negative charges in the nucleus. As yet, nobody seemed to suspect the existence of a neutral particle, without a charge.

He did, however, go on to explain the transformation of atoms by his displacement law. In this, the emission of an alpha particle, a helium nucleus of two protons and two neutrons, lowers the atomic weight by four while the emission of a beta particle, an electron, raises the atomic number by one. Given these rules Soddy could show how, for example, uranium and thorium could both decay, by different paths, to different isotopes of lead (Casimir Fajans independently suggested the same law).

Despite the award of the 1921 Nobel Prize for chemistry for his work on the origins and nature of isotopes, Soddy became disillusioned with science and his place in it. After 1919 Soddy took no further part in creative science. He wrote a good deal, mainly in the fields of economic and social questions, which raised little interest or support. On the issue of energy, however, he was remarkably perceptive. As early as 1912 he could comment that “the still unrecognized ‘energy problem’ … awaits the future,” continuing with the by now familiar refrain of our profligate use of hydrocarbons, “a legacy from the remote past,” and concluding with what he saw as our only hope, atomic energy, which “could provide anyone who wanted it with a private sun of his own.”

The English chemist Frederick Soddy (1877-1956) shared in the discoveries of atomic disintegration and of helium production during radioactive decay and introduced the term "isotope" to nuclear science.

Frederick Soddy was born at Eastbourne, Sussex, on Sept. 2, 1877. He studied at Eastbourne College; University College, Aberystwyth; and Merton College, Oxford, where in 1898 he received his degree in chemistry.

Radioactivity Studies at Montreal

Having accepted a demonstratorship in chemistry at McGill University, Montreal, Soddy found himself increasingly attracted by the work being done by Ernest Rutherford, then research professor of physics at the university. He joined Rutherford's team and brought to it his valuable experience as a chemist.

In a study of the radioactivity of thorium, Rutherford and Soddy added ammonia to a solution of a thorium salt, so precipitating out thorium hydroxide. When the insoluble material had been filtered off, the remaining solution still showed radioactivity. They established that this was due to a highly radioactive substance which they called thorium-X. Detailed measurements were made of the radioactivity of solution and precipitate over a number of weeks, and it became clear that different chemical species were involved in the process of radioactive decay over the period studied.

Further evidence for a strangely new kind of disintegration came from Rutherford's and Soddy's examination of the behavior of uranium, which when pure, emitted alpha particles only. The beta emission often encountered must therefore come from some other substance. Rutherford had already noted a gaseous emanation from thorium; now, with Soddy, he suggested that it belonged to the inert gas family. Also, they removed all doubts about the existence of a similar emanation from radium by condensing it with liquid air.

Soddy, who had long been interested in the historical problem of alchemy, now used the alchemical term "transmutation" to describe the changes that are accompanied by radioactive emission. Rutherford adopted the concept, and in 1903 they announced the general theory of radioactive disintegration. They proposed that radioactivity was an atomic phenomenon and that radiation was an accompaniment of chemical transmutations of the atoms themselves. This theory, though often bearing Rutherford's name alone, was in fact a product of the joint activity of Rutherford and Soddy.

Helium Studies at London

In 1903 Soddy left Montreal for London, drawn by the reputation of Sir William Ramsay at University College. Soddy was anxious to study further the gases associated with radioactive materials. Ramsay's laboratory, internationally acclaimed for the addition of the inert gases to the periodic table, was almost the only place where minute quantities of rare gases could be successfully examined.

Ramsay had recently acquired a small amount of radium bromide, and he and Soddy examined the gaseous emanations which were pumped off. After removal of oxygen and other common gases, the residue was examined spectroscopically. It was found to give the same spectrum as helium. When the gas was cooled by liquid air to remove the helium, the residue, as expected, gave no helium spectrum; but after a few days the helium line reappeared. Clearly helium had formed as a product of radioactive decay. Soddy concluded that the helium originated with the alpha particles, which were thus helium nuclei - a view later confirmed by Rutherford. Ramsay and Soddy showed that the other gaseous emanations were true inert gases.

Defining the Isotope at Glasgow

In 1904 Soddy moved to the University of Glasgow to take up a special appointment as lecturer in physical chemistry (including radiochemistry). During his first few years he made steady progress in purifying radioactive materials. In 1908 he married Winifred Beilby, only daughter of George Beilby of the Cassell Gold Extracting Company, which provided financial support for a research program in which Soddy was engaged involving methods of extraction for possible substitutes for radium. This project yielded few results of importance.

In 1910 Soddy turned his attention to the short-lived radioelements, collaborating with Alexander Fleck. They decided to establish the chemical characteristics of every known member of the disintegration series. They showed that in several cases a number of intermediates were chemically identical and inseparable from one another, yet underwent radioactive decay in quite different ways. Thus identical chemical properties were shown by radium-B, thorium-B, actinium-B, and lead.

Soddy's first generalization on these mysteries came in his rule that loss of an alpha particle from an atom with an even number in the periodic table produces an atom with the next lower even number. In subsequent changes, however, when alpha emission does not take place, a reversion to the original "family" may occur, and the products will be chemically inseparable from the starting material, even though the atomic weights vary. Complementary to this alpha-particle rule is the one that in beta emissions an atom moves up one place in the periodic table. In 1913 Soddy combined the alpha and beta rules into the group displacement law: one alpha emission causes a shift two places back in the periodic table, and one beta emission causes a shift one place further on. Hence a sequence of alpha-beta-beta emissions would mean a return to the original place in the table.

The underlying concept, that more than one kind of atom might be assignable to the same chemical "space," was daring and revolutionary. In December 1913 Soddy brought matters to a head by writing a letter to Nature in which he proposed that such chemically inseparable species should be termed "isotopes." In modern parlance, they differ from each other in mass but not in overall nuclear charge. The group displacement law and the related concept of isotopy were soon confirmed.

In 1914 Soddy became professor of chemistry at Aberdeen. His fortunes here were immediately and drastically affected by the war. He was able to complete some of the work begun in Glasgow, but his radiochemical researches were brought to a premature end by the special wartime demands made upon his laboratories.

Oxford and Retirement

With the ending of the war the future held great promise for radiochemical studies in Britain. In 1919 Soddy was appointed Lee's professor of inorganic and physical chemistry at the University of Oxford. Two years later he received the Nobel Prize in chemistry for his contributions to radio-chemistry and, particularly, to the concept of isotopes.

It was widely hoped that, under Soddy's leadership, a British school of radiochemistry would emerge at Oxford that would complement the work of the atomic physicists at the Cavendish Laboratory in Cambridge. Unfortunately this was not to be, for his output of original work in science was negligible. In 1936 he resigned his chair. The death of his wife no doubt contributed to his discontent, but this cannot explain the full measure of his apparent disenchantment with experimental work.

Soddy was an extremely talented writer, and to some extent his literary gifts may have interfered with his laboratory research. His first book, Radioactivity, appeared in 1904. For many years, beginning in 1904, he contributed articles on radioactivity to the Annual Reports of the Chemical Society. The Interpretation of Radium (1909) was a popular treatise deriving much from his Glasgow lectures. The Chemistry of the Radioelements (1910) was a concise and reliable summary of the contemporary position. Later works included The Interpretation of the Atom (1932) and The Story of Atomic Energy (1947). He also wrote several books on economic theory. He died on Sept. 21, 1956, in Brighton.

Further Reading

Muriel Howarth, Pioneer Research on the Atom (1958), contains a biography of Soddy. The Royal Society of London, Biographical Memoirs of Fellows of the Royal Society, vol. 3 (1957), has a biography of Soddy by Sir Alexander Fleck. Additional material is in Henry A. Boorse and Lloyd Motz, eds., The World of the Atom (2 vols., 1966).

Additional Sources

Frederick Soddy (1877-1956): early pioneer in radiochemistry, Dordrecht; Boston: D. Reidel Pub. Co.; Hingham, MA, U.S.A.: Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers, 1986.

Merricks, Linda, The world made new: Frederick Soddy, science, politics, and environment, New York: Oxford University Press, 1996.

Frederick Soddy
Born	2 September 1877(1877-09-02) Eastbourne, England
Died	22 September 1956 (aged 79) Brighton, England
Nationality	British
Fields	Radiochemistry
Institutions	McGill University (1900-1903) University of Glasgow (1904-1914) University of Aberdeen (1914-1919) Oxford University (1919-1936)
Alma mater	Aberystwyth University Merton College, Oxford
Academic advisors	Ernest Rutherford
Doctoral students	Iimori Satosayu
Known for	Nuclear transmutation of radioelements Radioisotopes Coining the term isotope Energy in economics Soddy's hexlet Soddy circles
Notable awards	Nobel Prize for Chemistry (1921) Lunar crater Soddy

Frederick Soddy (2 September 1877 – 22 September 1956) was an English radiochemist who explained, with Ernest Rutherford, that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also proved the existence of isotopes of certain radioactive elements. He received the Nobel Prize for Chemistry in 1921, and has a crater named for him on the far side of the Moon.

Contents 1 Biography 2 See also 3 Bibliography 4 References 5 External links

Biography

Soddy was born in Eastbourne, England. He went to school at Eastbourne College, before going on to study at University College of Wales at Aberystwyth and at Merton College, Oxford. He was a researcher at Oxford from 1898 to 1900. He married Winifred Beilby in 1908.

In 1900 he became a demonstrator in chemistry at McGill University in Montreal, Quebec, Canada, where he worked with Ernest Rutherford on radioactivity. He and Rutherford realized that the anomalous behaviour of radioactive elements was because they decayed into other elements. This decay also produced alpha, beta, and gamma radiation. When radioactivity was first discovered, no one was sure what the cause was. It needed careful work by Soddy and Rutherford to prove that atomic transmutation was in fact occurring.

His work and essays popularising the new understanding of radioactivity was the main inspiration for H. G. Wells's The World Set Free (1914), which features atomic bombs dropped from biplanes in a war set many years in the future. Wells's novel is also known as The Last War and imagines a peaceful world emerging from the chaos. In Wealth, Virtual Wealth and Debt Soddy praises Wells’s The World Set Free. He also says that radioactive processes probably power the stars.

In 1903, with Sir William Ramsay at University College London, Soddy verified that the decay of radium produced alpha particles composed of positively charged nuclei of helium. In the experiment a sample of radium was enclosed in a thin walled glass envelope sited within an evacuated glass bulb. Alpha particles could pass through the thin glass wall but were contained within the surrounding glass envelope. After leaving the experiment running for a long period of time a spectral analysis of the contents of the former evacuated space revealed the presence of helium. This element had recently been discovered in the solar spectrum by Bunsen and Kirchoff.^[1]

From 1904 to 1914, Soddy was a lecturer at the University of Glasgow and while there he showed that uranium decays to radium. It was here also that he showed that a radioactive element may have more than one atomic mass though the chemical properties are identical. He named this concept isotope meaning 'same place' - the word 'isotope' was initially suggested to him by Margaret Todd. Later, J.J. Thomson showed that non-radioactive elements can also have multiple isotopes. Soddy also showed that an atom moves lower in atomic number by two places on alpha emission, higher by one place on beta emission. This was a fundamental step toward understanding the relationships among families of radioactive elements.

Soddy published The Interpretation of Radium (1909) and Atomic Transmutation (1953). In 1914 he was appointed to a chair at the University of Aberdeen, where he worked on research related to World War I. In 1919 he moved to Oxford University as Dr Lee's Professor of Chemistry, where, in the period up till 1936, he reorganized the laboratories and the syllabus in chemistry. He received the 1921 Nobel Prize in chemistry for his research in radioactive decay and particularly for his formulation of the theory of isotopes.

In four books written from 1921 to 1934, Soddy carried on a "quixotic campaign for a radical restructuring of global monetary relationships", offering a perspective on economics rooted in physics -- the laws of thermodynamics, in particular -- and was "roundly dismissed as a crank".^[2]

He rediscovered the Descartes' theorem in 1936 and published it as a poem. The kissing circles in this problem are sometimes known as Soddy circles. The lunar crater Soddy is named after him. He died in Brighton, England.

See also

Wikiquote has a collection of quotations related to: Frederick Soddy

• Alfred J. Lotka
• Problem of Apollonius
• Ergosophy
• Econophysics

Bibliography

• Radioactivity (1904)
• The Interpretation of Radium (1909) (a searchable facsimile at the University of Georgia Libraries; DjVu & layered PDF format)
• The Chemistry of the Radioactive Elements (1912-1914)
• Matter and Energy (1912)
• Science and life: Aberdeen adresses (1920)
• Cartesian Economics: The Bearing of Physical Science upon State Stewardship (1921)
• Science and Life Wealth, Virtual Wealth, and Debt Money versus Man etc (1921)
• Nobel Lecture - The origins of the conception of isotopes (1922)
• Wealth, Virtual Wealth and Debt. The solution of the economic paradox (George Allen & Unwin, 1926)
• The wrecking of a scientific age (1927)
• The Interpretation of the Atom (1932)
• Money versus Man (1933)
• The Role of Money, Frederick Soddy (George Routledge & Sons Ltd, 1934. Internet Archive Gutenberg)
• Money as nothing for something ; The gold "standard" snare (1935)
• Present outlook, a warning : debasement of the currency, deflation and unemployment (1944)
• The Story of Atomic Energy (1949)
• Atomic Transmutation (1953)

References

1. ^ William Ramsay; Frederick Soddy (1903 - 1904). "Experiments in Radioactivity, and the Production of Helium from Radium". Proceedings of the Royal Society of London 72: 204–207. doi:10.1098/rspl.1903.0040. http://links.jstor.org/sici?sici=0370-1662%281903%2F1904%2972%3C204%3AEIRATP%3E2.0.CO%3B2-V. 
2. ^ "Mr. Soddy’s Ecological Economy", The New York Times, April 12, 2009.

• Mansel Davies (1992). "Frederick Soddy: The scientist as prophet". Annals of Science 49 (4): 351 – 367. doi:10.1080/00033799200200301. 
• George B. Kauffman (1997). "The World Made New: Frederick Soddy, Science, Politics, and Environment". Isis 88 (3): 564. doi:10.1086/383825. http://links.jstor.org/sici?sici=0021-1753%28199709%2988%3A3%3C564%3ATWMNFS%3E2.0.CO%3B2-F. 
• Daly, Herman E. Winter (1980). "The economic thought of Frederick Soddy". History of Political Economy 12 (4): 469–488. 
• Freeman M. I. (1979). "Soddy, Frederick and the Practical Significance of Radioactive Matter". Britisch Journal for the History of Science 12 (42): 257–260. doi:10.1017/S0007087400017313. 
• Richard E. Sclove (1989). "From Alchemy to Atomic War: Frederick Soddy's "Technology Assessment" of Atomic Energy, 1900-1915". Science, Technology, & Human Values 14 (2): 163. doi:10.1177/016224398901400203. http://links.jstor.org/sici?sici=0162-2439%28198921%2914%3A2%3C163%3AFATAWF%3E2.0.CO%3B2-2. , pp. 163-194
• Linda Merricks (1996). The World Made New: Frederick Soddy, Science, Politics, and Environment.. Oxford New York: Oxford University Press. pp. 223. ISBN 0198559348. 
• A. N. Krivomazov (1978). Frederick Soddy: 1877-1956.. Moscow: Nauka. pp. 208. 
• George B. Kauffman (1986). Frederick Soddy (1877-1956): Early Pioneer in Radiochemistry (Chemists and Chemistry). Dordrecht; Boston; Hingham: D. Reidel Pub. Co.. pp. 272. ISBN 978-9027719263. 

External links

• The Central Role of Energy in Soddy's Holistic and Critical Approach to Nuclear Science, Economics, and Social Responsibility
• Annotated bibliography for Frederick Soddy from the Alsos Digital Library for Nuclear Issues
• M. King Hubbert on the Nature of Growth. 1974
• A biography of Frederick Soddy by Arian Forrest Nevin

v • d • e Nobel Laureates in Chemistry Jacobus van 't Hoff (1901) · Emil Fischer (1902) · Svante Arrhenius (1903) · William Ramsay (1904) · Adolf von Baeyer (1905) · Henri Moissan (1906) · Eduard Buchner (1907) · Ernest Rutherford (1908) · Wilhelm Ostwald (1909) · Otto Wallach (1910) · Marie Curie (1911) · Victor Grignard / Paul Sabatier (1912) · Alfred Werner (1913) · Theodore Richards (1914) · Richard Willstätter (1915) · Fritz Haber (1918) · Walther Nernst (1920) · Frederick Soddy (1921) · Francis Aston (1922) · Fritz Pregl (1923) · Richard Zsigmondy (1925) Complete roster · 1901–1925 · 1926–1950 · 1951–1975 · 1976–2000 · 2001–present

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)