115 years ago Maria Skłodowska-Curie and her husband Pierre Curie received the Nobel Prize

In November 1891, Maria Skłodowska left Poland to study in France and began studies at the Faculty of Physics and Chemistry at the Sorbonne. She was the first woman who studied at this faculty. After two years, she was awarded a degree in physics as the best student, and in mathematics as the second best student.

In 1894 Skłodowska conducted research on the magnetism of metals. During that time, she met a Polish physicist in Paris - Józef Wierusz-Kowalski. Wierusz-Kowalski invited 35-year-old Pierre Curie - a well-known physicist, doctoral student devoted to his work - and recommended Skłodowska to him. He had promised Skłodowska to help her find a laboratory where she would be able to conduct her experiments.

That was when Maria and Pierre met, started working together, and with time developed an affection for each other. In 1895, they got married.

Two years later, in 1897, Maria Skłodowska graduated from the Sorbonne. The researcher began to look for the subject of a doctoral dissertation. She was interested in the rays emitted by minerals and uranium compounds, discovered in 1896 by Henri Becquerel. The rays would blacken photographic plates with the same intensity for months, which seemed to contradict the law of conservation of energy. Skłodowska decided to investigate this phenomenon, especially that this subject was completely new and had no bibliography.

The researcher decided to investigate whether, in addition to the radiation emitted by the uranium ore that made the air conduct electricity, some other minerals also behaved in the same way. During her research, Skłodowska discovered that uraninite (a mineral from uranium mine in Joachimstahl in Austria) and torbernite (uranyl phosphate) were more radioactive than uranium. This discovery led to the conclusion that both minerals could contain an unknown radioactive element.

Pierre Curie supported Maria during her work. He was so fascinated by the phenomenon observed by Skłodowska that he gave up his research on crystals and decided to help his wife find this mysterious element. The result of research conducted by the Curies was the discovery (in July 1898) of an element with strong radioactive properties - polonium.

"Some ores containing uranium and thorium (uraninite, torbernite, uranite) are very active in terms of emitting Becquerel radiation. In the previous study, one of us demonstrated that their activity is even stronger than the activity of uranium and thorium, and speculated that this fact should be attributed to a different and unusually active substance which is contained in these ores in very minuscule amounts […] We suspect that the body we isolated from the uraninite contains a yet unknown metal similar to bismuth in its chemical properties. If the existence of this metal is confirmed, we propose to name it ‘polonium’ after the homeland of one of us" - Maria Skłodowska-Curie wrote about her research.

From the beginning of their research, Maria and Pierre Curie suspected that there was a second radioactive element in uraninite that behaved chemically like a barium. That hypothesis was also confirmed. In the conclusion of the article "On a new, very radioactive substance, contained in uraninite", which was sent to the Academy of Sciences, Maria and Pierre Curie wrote: "a radioactive substance contains a new element, which we propose to name +radium+".

On June 13, 1903, Maria Skłodowska-Curie, as the first woman in France, defended her doctoral dissertation entitled "Research on Radioactive Substances". Physicist Edmond Bouty, as well as two academics and future Nobel Prize winners, Gabriel Lippmann and Henri Moissan, recognized Skłodowska`s findings as the most important ones ever presented in a doctoral dissertation.

In 1903 Henri Becquerel and Pierre Curie were nominated for the Nobel Prize in Physics, while Maria Skłodowska was omitted. Pierre Curie sent a firm letter addressed to physicist Henri Poincaré, in which he demanded that the prize be shared with Maria.

Pierre Curie wrote: "If it is true that one is seriously thinking about me [for the Prize] I very much wish to be considered together with Madame Curie with respect to our research on radioactive bodies. Do you not think that it would be more satisfying from the artistic point of view, if we were to be associated in this manner? […] her role in this discovery was very important (she also determined the atomic weight of radium)".

Ultimately, Maria Skłodowska was also incorporated into the nomination for the Nobel Prize in Physics.

On October 12, 1903, the Royal Swedish Academy of Sciences awarded the Nobel Prize in Physics. The Prize was divided, one half awarded to Antoine Henri Becquerel "in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity", the other half jointly to Pierre Curie and Marie Curie, née Sklodowska "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel".

The Curies were expected to come to Stockholm on December 10 for the official award ceremony and give a public lecture. But they chose not to attend the ceremony - they did not want to disrupt their teaching duties, and Maria`s recent illness was another reason. The French ambassador received the diploma and medal on behalf of the Curies. Maria Skłodowska-Curie and Pierre Curie went to Sweden two years later, in June 1905.

Awarding of the Nobel Prize in Physics to Maria Skłodowska-Curie meant that for the first time in history this prize was awarded to a woman.

The Nobel Prize changed the life of the couple: Pierre Curie was given the chair of physics at the Sorbonne, while Maria, tired of research on radioactivity, the PhD defence and the publicity that followed the award of Nobel Prize, stopped working in the laboratory for three years and focused on her children: Irena (born in 1897) and Ewa (born in 1904).

In January 1906, Pierre Curie died in an accident - he was run over by a horse-drawn wagon. Maria was broken down by her husband`s sudden death of, she started to write a journal in which she described her painful experience. But she returned to intensive research work in her laboratory. She focused on new radioactive elements, managed to obtain radium in the metallic state, improved methods for obtaining other substances. She also actively participated in international scientific conferences.

On November 10, 1911, the Royal Swedish Academy of Sciences awarded her the Nobel Prize in Chemistry for the discovery of radium and polonium. She received the Prize on December 10, 1911. In the justification, the Nobel Foundation`s Scientific Committee of Chemistry announced that it awarded the individual prize "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element".

At the award ceremony, the President the Academy addressed Skłodowska in his speech: " In 1903, the Swedish Academy of Sciences had the honour of conferring upon you the Nobel Prize for Physics for the part which you, together with your late husband, took in the momentous discovery of spontaneous radioactivity. This year, the Academy has decided to award you the prize for Chemistry in recognition of the eminent services you have rendered to this science by your discovery of radium and polonium, by your description of the characteristics of radium and its isolation in the metallic state, and by your research into the compounds of this remarkable element. During the eleven years in which Nobel Prizes have been awarded, this is the first time that the distinction has been conferred upon a previous prizewinner. I beg you, Madam, to see in this circumstance a proof of the importance which our Academy attaches to your most recent discoveries".

Anna Kruszyńska (PAP)

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