She described fission first. They called it ridiculous.

In September 1934 a German chemist published a short paper pointing out that Enrico Fermi had not proved what he claimed to have proved, and offering an alternative that nobody wanted.

Four years later two men in Berlin demonstrated that the alternative was correct. One of them had called her suggestion ridiculous. He collected the Nobel Prize for it.

Her name was Ida Noddack.

The chemist

She was born Ida Tacke on 25 February 1896 in Lackhausen, in the northern Rhine region, now part of Wesel. Her father owned a small varnish factory. Her own account of why she chose chemistry is unsentimental: she did not want to teach, industry and research employed few physicists at the time, so chemistry it was, a decision her father welcomed.

She entered the Technische Hochschule Charlottenburg in Berlin in 1915, six years after Berlin’s universities opened to women. Nine of the eighty-five students in her year were studying chemistry. She took her Diplom-Ingenieur in 1919, winning the school’s first prize for chemistry and metallurgy, and her Doktor-Ingenieur in 1921 on higher aliphatic fatty acid anhydrides.

She worked as a chemist at AEG in Berlin, then at Siemens-Halske, and in 1925 joined the Physikalisch-Technische Reichsanstalt, a government laboratory whose chemical division was headed by Walter Noddack. They married the following year and worked from then on as what they called an Arbeitsgemeinschaft, a work unit.

The search they took up was for the two gaps Mendeleev had left below manganese. Everyone before them had hunted in manganese ores, on the assumption that the missing elements would behave like manganese. Tacke’s reasoning was that they would instead resemble their horizontal neighbours, which meant looking in ores of molybdenum, tungsten, ruthenium and osmium. That inversion is the whole discovery.

In June 1925, with Otto Berg, an x-ray specialist at Siemens-Halske, they identified a new element spectroscopically in a sample of Norwegian columbite. They named it rhenium, for the Rhine. A year later they had extracted the first gram of the metal from 660 kilograms of molybdenite ore. They also announced a second element, masurium, at 43.

Rhenium held. It is element 75, one of the last stable elements found in nature, and it is hers. That same year she became the first woman to give a major address to the Society of German Chemists. The German Chemical Society gave the Noddacks the Liebig Medal in 1931 and the Swedish Chemical Society the Scheele Medal in 1934, and she was nominated for the Nobel Prize more than once during the 1930s.

Masurium did not hold, and the argument about it has never fully closed. This matters, and it is dealt with below rather than left out.

What she wrote in 1934

In 1934 Fermi bombarded uranium with neutrons in Rome and found a new radioactivity that behaved chemically unlike uranium or anything near it. He published in Nature under the title “Possible Production of Elements of Atomic Number Higher than 92.” The conclusion was that he had made elements past the end of the periodic table.

Noddack published a response in Angewandte Chemie that September, titled “Über das Element 93.” Her central criticism was analytical, and it was correct. Fermi had ruled out the elements immediately below uranium. He had not ruled out the rest of the table. He had eliminated candidates down to lead and stopped.

Then she wrote the sentence. When heavy nuclei are bombarded by neutrons, she said, it would be reasonable to conceive that they break down into numerous large fragments which are isotopes of known elements but are not neighbours of the bombarded elements.

That is nuclear fission, stated in print, four years before it was demonstrated and five before it was named.

The paper was ignored. Where it was noticed it was mocked. Otto Hahn, the leading radiochemist in Germany, regarded the suggestion as ridiculous.

Why it was dismissed, honestly stated

There were reasons that had nothing to do with her sex, and this archive states them rather than routing around them.

Noddack offered no experimental evidence for the breakup. She offered no theoretical mechanism either, and in 1934 no accepted model of the nucleus permitted one. The Bohr liquid-drop picture that eventually made fission intelligible was not available. Her proposal was a single sentence in a paper whose main business was criticising someone else’s chemistry, and she did not go into the laboratory and test it.

Set against that: her analytical objection to Fermi was flatly right, and nobody acted on that either. The chemistry was checkable by anyone with a bench and four years of running room. Hahn had both.

There is also the part of the record that complicates any attempt to make her a martyr. Noddack worked within, and benefited from, the German academic establishment as it was reorganised under the Nazi government in the 1930s. Brigitte Van Tiggelen of the Science History Institute puts the difficulty plainly: readers want a heroine or a martyr, and Ida Noddack does not fit the description. Her wartime position likely clouded the post-war assessment of everything she had done.

Both things are in the record. The archive keeps both.

December 1938

On 17 December 1938, Otto Hahn and Fritz Strassmann established by chemical analysis that the products of neutron-bombarded uranium included isotopes of barium. Barium sits at 56. Uranium sits at 92. The nucleus had broken into large fragments that were not neighbours of the irradiated element.

Hahn wrote to Lise Meitner, by then in exile in Sweden, describing a bursting of the nucleus. Meitner and Otto Frisch supplied the theoretical account, using the liquid-drop model, and Frisch gave the process its name.

Hahn announced the barium result in January 1939. He had spent the previous five years repeating and extending Fermi’s work and publishing on the transuranic elements that were not there.

In 1939 Noddack stated publicly that she had proposed this in 1934. Hahn and Strassmann did not answer her.

The Nobel Prize in Chemistry for 1944 went to Otto Hahn alone, for the discovery of the fission of heavy nuclei. He received it in 1945, the committee having reserved the 1944 prize for a year.

The masurium problem

Element 43 has to be addressed directly, because it is the thing most often used to dismiss her, and because the honest answer is that she was probably wrong.

The Noddacks could not reproduce their masurium result and could not isolate the element. Element 43 was produced in 1937 by Emilio Segrè and Carlo Perrier from irradiated molybdenum and named technetium, for its artificial origin. No isotope of it lasts long enough to survive in ores in meaningful quantity.

In 1988 Pieter van Assche reanalysed the Noddacks’ data and argued their detection limit was far lower than reported, which would have let them see trace technetium from spontaneous uranium fission in their ores. John Armstrong at NIST simulated the spectra and found the agreement striking. That work drove a partial rehabilitation.

It did not survive scrutiny. Günter Herrmann examined van Assche’s reasoning and concluded it was constructed after the fact and forced toward a predetermined result. Paul Kuroda concluded there was no reason to believe the Noddacks had found element 43. Roberto Zingales, who had published the rehabilitation account, later wrote to the Journal of Chemical Education correcting himself.

So: rhenium is hers and secure. Masurium is not. And her claim on fission does not depend on either.

What the record shows

Noddack kept working. She and Walter moved to Freiburg in 1935, to Strasbourg in 1942, and in 1956 to a newly founded state institute for geochemistry at Bamberg. She published on the abundance of the elements, on heavy metals in marine animals, and in 1942 a book on the development and structure of chemical science. Walter died in 1960. She retired in 1968 and spent her last years in an apartment building for the elderly at Bad Neuenahr, where she died on 24 September 1978, aged eighty-two.

There is one more entry in the record. In October 1969 the Soviet Academy of Sciences invited her to Leningrad for the centenary of Mendeleev’s periodic table. She was by then the only living chemist who had discovered a naturally occurring element. She was too ill to travel. Her paper was translated into Russian and read out for her, and in it she set down her own account of the discovery and of the transuranic argument she believed had tainted her career.

Emilio Segrè, who had isolated element 43 and named it technetium, was in the room.

She had been right about the chemistry in 1934, and right about the physics in a sentence she could not prove, and the man who called it ridiculous went on to prove it and take the prize and never answer her.

The archive grows. The silence shrinks. Enter the archive.

Sources:

Ida Noddack and the missing elements — Fathi Habashi, Education in Chemistry 46, no. 2, Royal Society of Chemistry, March 2009. Full text, open access. The fullest account of the rhenium search, the 1934 paper, and the 1969 Leningrad invitation, by a chemist who knew her.
A tale of oblivion: Ida Noddack and the ‘universal abundance’ of matter — Gildo Magalhães Santos, Notes and Records of the Royal Society of London 68 (2014). Full text, open access. The scholarly treatment of the Hahn and Strassmann dispute.
Ida Noddack and the trouble with element 43 — Rachel Brazil, Chemistry World, Royal Society of Chemistry. Source of the Van Tiggelen assessment. Body text sits behind a registration wall.
Possible Production of Elements of Atomic Number Higher than 92 — Enrico Fermi, Nature 133 (1934): 898–899. The paper she answered. Abstract open, full text paywalled.
The Nobel Prize in Chemistry 1944 — The Nobel Foundation. Awarded to Otto Hahn alone, and delivered in 1945.
Ida Noddack — Erik Gregersen, Encyclopædia Britannica
Ida Noddack, “Über das Element 93,” Zeitschrift für Angewandte Chemie 47, no. 37 (September 1934): 653–655. DOI 10.1002/ange.19340473707. The primary document. The publisher record resolves but returns no readable text, and the widely circulated English translation now exists only in web archive copies that cannot be linked reliably. Quoted here via Habashi’s translation above.
Annette Lykknes, Donald L. Opitz and Brigitte Van Tiggelen, eds., For Better or For Worse? Collaborative Couples in the Sciences (Birkhäuser, 2012). Source for the Arbeitsgemeinschaft working arrangement. Print only, no open-access edition.
Günter Herrmann, “Technetium or masurium: a comment on the history of element 43,” Nuclear Physics A 505, no. 2 (1989): 352–360. Print and paywalled, no open-access edition.
Paul K. Kuroda, “A Note on the Discovery of Technetium,” Nuclear Physics A 503, no. 1 (1989): 178–182. Print and paywalled, no open-access edition.