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Skłodowska-Curie w Wikipedii

Skłodowska-Curie w Wikipedii

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Marie Curie

Marie Skłodowska-Curie (7 November 1867 – 4 July 1934) was a Polish-born French physicist and chemist famous for her work on radioactivity. She was a pioneer in the field of radioactivity and the first person honored with two Nobel Prizes —in physics and chemistry. She was also the first female professor at the University of Paris.

Maria Skłodowska was born in Warsaw (in Vistula Land, Russian Empire by then; now in Poland) and lived there until she was twenty-four. In 1891 she followed her older sister Bronisława to study in Paris, where she obtained her higher degrees and conducted her subsequent scientific work. She founded the Curie Institutes in Paris and Warsaw. Her husband Pierre Curie shared her Nobel prize in physics. Her daughter Irène Joliot-Curie and son-in-law, Frédéric Joliot-Curie, also shared a Nobel prize. She was the sole winner of the 1911 Nobel Prize for Chemistry. Curie was the first woman to win a Nobel Prize, and she is the only woman to win the award in two different fields and only person to win the award in multiple sciences.

Her achievements include the creation of a theory of radioactivity (a term she coined), techniques for isolating radioactive isotopes, and the discovery of two new elements, polonium and radium. Under her direction, the world's first studies were conducted into the treatment of neoplasms -- including cancers -- using radioactive isotopes.

While an actively loyal French citizen, she never lost her sense of Polish identity. She named the first new chemical element that she discovered polonium (1898) for her native country, and in 1932 she founded a Radium Institute (now the Maria Skłodowska–Curie Institute of Oncology) in her home town, Warsaw, headed by her sister Bronisława - physician.

Early life

Maria Skłodowska was born as the fifth and youngest child of well-known teachers Bronisława and Władysław Skłodowski. Maria's older siblings were Zofia (born 1862), Józef (1863), Bronisława (1865), and Helena (1866).

Maria's grandfather Józef Skłodowski had been a respected teacher in Lublin. Her father Władysław Skłodowski taught mathematics and physics, subjects that Maria was to pursue, and he also was director of two Warsaw gymnasia for boys, in addition to lodging boys in the family home. Her mother, Bronisława, operated a prestigious Warsaw boarding school for girls. She suffered from tuberculosis and died when Maria was twelve.

Maria's father was an atheist and her mother a devout Catholic. Two years earlier, Maria's oldest sibling, Zofia, had died of typhus. The deaths of her mother and sister, according to Robert William Reid, caused Maria to give up Catholicism and become agnostic.

When she was ten years old, Maria began attending the boarding school that her mother had operated while she was well; next Maria attended a gymnasium for girls, from which she graduated on 12 June 1883. She spent the following year in the countryside with her father's relatives, and the next with her father in Warsaw, where she did some tutoring.

On both the paternal and maternal sides, the family had lost their property and fortunes through patriotic involvements in Polish national uprisings. This condemned each subsequent generation, including that of Maria, her elder sisters, and brother to a difficult struggle to get ahead in life.

Maria made an agreement with her sister, Bronisława, that she would give her financial assistance during Bronisława's medical studies in Paris, in exchange for similar assistance two years later. In connection with this, Maria took a position as governess: first with a lawyer's family in Kraków; then for two years in Ciechanów with a landed family, the Żórawskis, who were relatives of her father. While working for the latter family, she fell in love with their son, Kazimierz Żórawski, which was reciprocated by this future eminent mathematician. His parents, however, rejected the idea of his marrying the penniless relative, and Kazimierz was unable to oppose them. Maria lost her position as governess. She found another with the Fuchs family in Sopot, on the Baltic Sea coast, where she spent the next year, all the while financially assisting her sister.

At the beginning of 1890, Bronisława, a few months after she married Kazimierz Dłuski, invited Maria to join them in Paris. Maria declined because she could not afford the university tuition and was still counting on marrying Kazimierz Żórawski. She returned home to her father in Warsaw, where she remained till the fall of 1891. She tutored, studied at the clandestine Floating University, and began her practical scientific training in a laboratory at the Museum of Industry and Agriculture at Krakowskie Przedmieście 66, near Warsaw's Old Town. The laboratory was run by her cousin Józef Boguski, who had been assistant in St. Petersburg to the great Russian chemist Dmitri Mendeleev.

In October 1891, at her sister's insistence and after receiving a letter from Żórawski, in which he definitively broke up his relationship with her, she decided to go to France after all.

The loss of the relationship was tragic for both: Maria Skłodowska and Kazimierz Żórawski. He soon earned a doctorate and pursued an academic career as a mathematician, becoming a professor and rector of Kraków University and president of the Warsaw Society of Learning. Still, as an old man and a mathematics professor at the Warsaw Polytechnic, he would sit contemplatively before the statue of Maria Skłodowska which had been erected in 1935 before the Radium Institute that she had founded in 1932.

In Paris, Maria briefly found shelter with her sister and brother-in-law before renting a primitive garret and proceeding with her studies of physics, chemistry, and mathematics at the Sorbonne (the University of Paris).

Sorbonne

In 1891 Skłodowska - as the first woman in history - got accepted on the physics and chemistery department at the Sorbonne. She has studied during the day and tutored in evenings, barely earning her keep. In 1893, she was awarded a degree in physics and began work at Lippman's industrial laboratory. Meanwhile she continued studying at the Sorbonne, and in 1894, earned a degree in mathematics.

That same year she had met Pierre Curie. He was an instructor at the School of Physics and Chemistry, the École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI). Skłodowska had begun her scientific career in Paris with an investigation of the magnetic properties of various steels; it was their mutual interest in magnetism that drew Skłodowska and Curie together.

Her departure for the summer to Warsaw only enhanced their mutual feelings for each other. She still was laboring under the illusion that she would be able to return to Poland and work in her chosen field of study. When she was denied a post in Kraków at Jagiellonian University merely because she was a woman, she decided to return to Paris. Almost a year later, in July 1895, she and Pierre Curie married, and thereafter the two physicists hardly ever left their laboratory. They shared two hobbies, long bicycle trips and journeys abroad, which brought them even closer. Maria had found a new love, a partner, and scientific collaborator upon whom she could depend.

New elements

In 1896, Henri Becquerel discovered that uranium salts emitted rays that resembled X-rays in their penetrating power. He demonstrated that this radiation, unlike phosphorescence, did not depend on an external source of energy, but seemed to arise spontaneously from uranium itself. Becquerel had, in fact, discovered radioactivity.

Skłodowska-Curie decided to look into uranium rays as a possible field of research for a thesis. She used a clever technique to investigate samples. Fifteen years earlier, her husband and his brother had invented the electrometer, a sensitive device for measuring electrical charge. Using electrometer, she discovered that uranium rays caused the air around a sample to conduct electricity. Using this technique, her first result was the finding that the activity of the uranium compounds depended only on the quantity of uranium present. She had shown that the radiation was not the outcome of some interaction of molecules, but must come from the atom itself. In scientific terms, this was the most important single piece of work that she conducted.

Skłodowska-Curie's systematic studies had included two uranium minerals, pitchblende and torbernite (also known as chalcolite). Her electrometer showed that pitchblende was four times as active as uranium itself, and chalcolite twice as active. She concluded that, if her earlier results relating the quantity of uranium to its activity were correct, then these two minerals must contain small quantities of some other substance that was far more active than uranium itself.

The idea [writes Reid] was her own; no one helped her formulate it, and although she took it to her husband for his opinion she clearly established her ownership of it. She later recorded the fact twice in her biography of her husband to ensure there was no chance whatever of any ambiguity. It [is] likely that already at this early stage of her career [she] realized that... many scientists would find it difficult to believe that a woman could be capable of the original work in which she was involved.

In her systematic search for other substances beside uranium salts that emitted radiation, Skłodowska-Curie had found that the element thorium likewise, was radioactive.

She was acutely aware of the importance of promptly publishing her discoveries and thus establishing her priority. Had not Becquerel, two years earlier, presented his discovery to the Académie des Sciences the day after he made it, credit for the discovery of radioactivity, and even a Nobel Prize, would have gone to Silvanus Thompson instead. Skłodowska-Curie chose the same rapid means of publication. Her paper, giving a brief and simple account of her work, was presented for her to the Académie on 12 April 1898 by her former professor, Gabriel Lippmann.

Even so, just as Thompson had been beaten by Becquerel, so Skłodowska-Curie was beaten in the race to tell of her discovery that thorium gives off rays in the same way as uranium. Two months earlier, Gerhard Schmidt had published his own finding in Berlin.

At that time, however, no one else in the world of physics had noticed what Skłodowska-Curie recorded in a sentence of her paper, describing how much greater were the activities of pitchblende and chalcolite compared to uranium itself: "The fact is very remarkable, and leads to the belief that these minerals may contain an element which is much more active than uranium." She later would recall how she felt "a passionate desire to verify this hypothesis as rapidly as possible."

Pierre Curie was sure that what she had discovered was not a spurious effect. He was so intrigued that he decided to drop his work on crystals temporarily and to join her. On April 14, 1898, they optimistically weighed out a 100-gram sample of pitchblende and ground it with a pestle and mortar. They did not realize at the time that what they were searching for was present in such minute quantities that they eventually would have to process tonnes of the ore.

As they were unaware of the deleterious effects of radiation exposure attendant on their chronic unprotected work with radioactive substances, Skłodowska-Curie and her husband had no idea what price they would pay for the effect of their research upon their health.

In July 1898, Skłodowska-Curie and her husband published a paper together, announcing the existence of an element which they named "polonium", in honor of her native Poland, which would for another twenty years remain partitioned among three empires. On December 26, 1898, the Curies announced the existence of a second element, which they named "radium" for its intense radioactivity — a word that they coined.

Pitchblende is a complex mineral. The chemical separation of its constituents was an arduous task. The discovery of polonium had been relatively easy; chemically it resembles the element bismuth, and polonium was the only bismuth-like substance in the ore. Radium, however, was more elusive. It is closely related, chemically, to barium, and pitchblende contains both elements. By 1898, the Curies had obtained traces of radium, but appreciable quantities, uncontaminated with barium, still were beyond reach.

The Curies undertook the arduous task of separating out radium salt by differential crystallization. From a ton of pitchblende, one-tenth of a gram of radium chloride was separated in 1902. By 1910, Skłodowska-Curie, working on without her husband, who had been killed accidentally by a horse drawn vehicle in 1906, had isolated the pure radium metal.

In an unusual decision, Marie Skłodowska-Curie intentionally refrained from patenting the radium-isolation process, so that the scientific community could do research unhindered.

In 1903, under the supervision of Henri Becquerel, Marie was awarded her DSc from the University of Paris.

Nobel Prizes

In 1903, the Royal Swedish Academy of Sciences awarded Pierre Curie, Marie Curie and Henri Becquerel the Nobel Prize in Physics, "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel".

Skłodowska-Curie and her husband were unable to go to Stockholm to receive the prize in person, but they shared its financial proceeds with needy acquaintances, including students.

On receiving the Nobel Prize, Marie and Pierre Curie suddenly became very famous. The Sorbonne gave Pierre a professorship and permitted him to establish his own laboratory, in which Skłodowska-Curie became the director of research.

In 1897 and 1904, respectively, Skłodowska-Curie gave birth to their daughters, Irène and Eve Curie. She later hired Polish governesses to teach her daughters her native language, and sent or took them on visits to Poland.

Skłodowska-Curie was the first woman to be awarded a Nobel Prize. Eight years later, she would receive the 1911 Nobel Prize in Chemistry, "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".

A month after accepting her 1911 Nobel Prize, she was hospitalized with depression and a kidney ailment.

Skłodowska-Curie was the first person to win or share two Nobel Prizes. She is one of only two people who have been awarded a Nobel Prize in two different fields, the other person being Linus Pauling (for chemistry and for peace). Nevertheless, in 1911 the French Academy of Sciences refused to abandon its prejudice against women, and she failed by two votes to be elected a member. Elected instead was Édouard Branly, an inventor who had helped Guglielmo Marconi develop the wireless telegraph. It would be a doctoral student of Skłodowska-Curie, Marguerite Perey, who would become the first woman elected to membership in the Academy — over half a century later, in 1962.

Pierre's death

On 19 April 1906, Pierre was killed in a street accident. Walking across the Rue Dauphine in heavy rain, he was struck by a horse-drawn vehicle and fell under its wheels, his skull was fractured. While it has been speculated that previously he may have been weakened by prolonged radiation exposure, there are no indications that this contributed to the accident.

Skłodowska-Curie was devastated by the death of her husband. She noted that, as of that moment she suddenly had become "an incurably and wretchedly lonely person". On 13 May 1906, the Sorbonne physics department decided to retain the chair that had been created for Pierre Curie and they entrusted it to Skłodowska-Curie together with full authority over the laboratory. This allowed her to emerge from Pierre's shadow. She became the first woman to become a professor at the Sorbonne, and in her exhausting work regime she sought a meaning for her life.

Recognition for her work grew to new heights, and in 1911 the Royal Swedish Academy of Sciences awarded her a second Nobel Prize, this time for Chemistry. A delegation of celebrated Polish men of learning, headed by world-famous novelist, Henryk Sienkiewicz, encouraged her to return to Poland and continue her research in her native country.

In 1911, it was revealed that during 1910–11 Skłodowska-Curie had conducted an affair of about a year's duration with physicist Paul Langevin, a former student of Pierre Curie. He was a married man who was estranged from his wife. This resulted in a press scandal that was exploited by her academic opponents. Despite her fame as a scientist working for France, the public's attitude tended toward xenophobia — the same that had led to the Dreyfus Affair — which also fueled false speculation that Skłodowska-Curie was Jewish. She was five years older than Langevin and was portrayed in the tabloids as a home-wrecker. Later, Skłodowska-Curie's granddaughter, Hélène Joliot, married Langevin's grandson, Michel Langevin.

Skłodowska-Curie's second Nobel Prize, in 1911, enabled her to talk the French government into funding the building of a private Radium Institute (Institut du radium, now the Institut Curie), which was built in 1914 and at which research was conducted in chemistry, physics, and medicine. The Institute became a crucible of Nobel Prize winners, producing four more, including her daughter Irène Joliot-Curie and her son-in-law, Frédéric Joliot-Curie.

World War I

During World War I, Skłodowska-Curie pushed for the use of mobile radiography units, which came to be popularly known as petites Curies ("Little Curies"), for the treatment of wounded soldiers. These units were powered using tubes of radium emanation, a colorless, radioactive gas given off by radium, later identified as radon. Skłodowska-Curie provided the tubes of radium, derived from the material she purified. Also, promptly after the war started, she donated the gold Nobel Prize medals she and her husband had been awarded, to the war effort.

Post-war years

In 1921, Skłodowska-Curie was welcomed triumphantly when she toured the United States to raise funds for research on radium. These distractions from her scientific labors and the attendant publicity caused her much discomfort but provided resources needed for her work. Her second American tour in 1929 succeeded in equipping the Warsaw Radium Institute, founded in 1925 with her sister, Bronisława, as director.

In her later years, Skłodowska-Curie headed the Pasteur Institute and a radioactivity laboratory created for her by the University of Paris.

Death

Skłodowska-Curie visited Poland for the last time in the spring of 1934. Only a few months later, on July 4, 1934, Skłodowska-Curie died at the Sancellemoz Sanatorium in Passy, in Haute-Savoie, eastern France, from aplastic anemia contracted from exposure to radiation. The damaging effects of ionizing radiation were not then known, and much of her work had been carried out in a shed, without proper safety measures. She had carried test tubes containing radioactive isotopes in her pocket and stored them in her desk drawer, remarking on the pretty blue-green light that the substances gave off in the dark.

She was interred at the cemetery in Sceaux, alongside her husband Pierre. Sixty years later, in 1995, in honor of their achievements, the remains of both were transferred to the Paris Panthéon. She became the first – and so far the only – woman to be honored with interrment in the Panthéon on her own merits.

Her laboratory is preserved at the Musée Curie.

Because of their levels of radioactivity, her papers from the 1890s are considered too dangerous to handle. Even her cookbook is highly radioactive. They are kept in lead-lined boxes, and those who wish to consult them must wear protective clothing.

Legacy

The physical and societal aspects of the work of the Curies contributed substantially to shaping the world of the twentieth and twenty-first centuries. Cornell University professor L. Pearce Williams observes:

The result of the Curies' work was epoch-making. Radium's radioactivity was so great that it could not be ignored. It seemed to contradict the principle of the conservation of energy and therefore forced a reconsideration of the foundations of physics. On the experimental level the discovery of radium provided men like Ernest Rutherford with sources of radioactivity with which they could probe the structure of the atom. As a result of Rutherford's experiments with alpha radiation, the nuclear atom was first postulated. In medicine, the radioactivity of radium appeared to offer a means by which cancer could be successfully attacked.

If the work of Maria Skłodowska-Curie helped overturn established ideas in physics and chemistry, it has had an equally profound effect in the societal sphere. To attain her scientific achievements, she had to overcome barriers that were placed in her way because she was a woman, in both her native and her adoptive country. This aspect of her life and career is highlighted in Françoise Giroud's Marie Curie: A Life, which emphasizes Skłodowska's role as a feminist precursor. She was ahead of her time, emancipated, independent, and in addition uncorrupted. Albert Einstein is reported to have remarked that she was probably the only person who was not corrupted by the fame that she had won.

Awards

• Nobel Prize in Physics (1903)
• Davy Medal (1903)
• Matteucci Medal (1904)
• Elliott Cresson Medal (1909)
• Nobel Prize in Chemistry (1911)

Marie Skłodowska-Curie is the first person to win two Nobel Prizes, and first woman among all receivers.

Honors

Madame Curie was decorated with the French Legion of Honor. In Poland, she had received honorary doctorates from the Lwów Polytechnic (1912), Poznań University (1922), Kraków's Jagiellonian University (1924), and the Warsaw Polytechnic (1926).

Their elder daughter, Irène Joliot-Curie, won a Nobel Prize for Chemistry in 1935 for discovering that aluminum could be made radioactive and emit neutrons when bombarded with alpha rays. Their younger daughter, Ève Curie, later wrote a biography of her mother.

Michalina Mościcka, wife of Polish President Ignacy Mościcki, unveiled a 1935 statue of Marie Curie before Warsaw's Radium Institute, which had been founded by Marie Curie. Within a decade, during the 1944 Warsaw Uprising, the monument suffered damage from gunfire. After the war, when maintenance was done, it was decided to leave the bullet-inflicted scars on the statue.

In 1967, a museum devoted to Skłodowska-Curie was established in Warsaw's "New Town", in her birthplace on ulica Freta (Freta Street).

The year 2011 has been declared the Year of Marie Curie by France and Poland.

Tributes

As one of the most famous female scientists to date, Marie Curie has been an icon in the scientific world and has inspired many tributes and recognitions. In 1995, she was the first woman laid to rest under the famous dome of the Paris Panthéon, alongside her husband, Pierre Curie.

The curie (symbol Ci), a unit of radioactivity, is named in honour of her and Pierre, as is the element with atomic number 96 — curium. Three radioactive minerals are also named after the Curies: curite, sklodowskite, and cuprosklodowskite.

Polish institutions named after Maria Skłodowska-Curie include:

• Maria Curie-Skłodowska University, in Lublin, founded in 1944;
• Maria Skłodowska-Curie Institute of Oncology, in Warsaw.

French institutions named after Maria Skłodowska-Curie include:

• Pierre and Marie Curie University, the largest science, technology, and medicine university in France, and the successor institution to the faculty of science at the University of Paris, where she taught; it is named in honor of her and Pierre. The university is home to the laboratory where they discovered radium.
• The Curie Institute and Curie Museum, in Paris.

Also in 2007, the Pierre Curie Paris Métro station was renamed the "Pierre et Marie Curie" station.

A KLM McDonnell Douglas MD-11 (registration PH-KCC) is named in her honor.

Skłodowska-Curie's likeness appeared on the Polish late-1980s inflationary 20,000-złoty banknote. Her likeness also has appeared on stamps and coins, as well as on the last French 500-franc note, before the franc was replaced by the euro.

Marie Curie was voted the "Most inspirational woman in science" in a 2009 poll carried out by New Scientist magazine on behalf of the L'Oréal UNESCO 'For Women In Science' programme. Curie received 25.1 per cent of all the votes cast, nearly twice as many as second-place Rosalind Franklin (14.2 per cent).

Greer Garson and Walter Pidgeon starred in the 1943 U.S. Oscar-nominated film, Madame Curie, based on her life. "Marie Curie" also is the name of a character in a 1988 comedy, Young Einstein, by Yahoo Serious.

More recently, in 1997, a French film about Pierre and Marie Curie was released, Les Palmes de M. Schutz. It was adapted from a play of the same name. In the film, Marie Curie was played by Isabelle Huppert. Unlike the 1943 drama, Les Palmes de M. Shutz is a light comedy.

References

• Robert Reid, Marie Curie, New York, New American Library, 1974.
• Teresa Kaczorowska, Córka mazowieckich równin, czyli Maria Skłodowska–Curie z Mazowsza (Daughter of the Mazovian Plains: Maria Skłodowska–Curie of Mazowsze), Ciechanów, 2007.
• Wojciech A. Wierzewski, "Mazowieckie korzenie Marii" ("Maria's Mazowsze Roots"), Gwiazda Polarna (The Pole Star), a Polish-American biweekly, no. 13, 21 June 2008, pp. 16–17.
• L. Pearce Williams, "Curie, Pierre and Marie", Encyclopedia Americana, Danbury, Connecticut, Grolier, Inc., 1986, vol. 8, pp. 331–32.
• Barbara Goldsmith, Obsessive Genius: The Inner World of Marie Curie, New York, W.W. Norton, 2005, ISBN 0-393-05137-4.
• Naomi Pasachoff, Marie Curie and the Science of Radioactivity, New York, Oxford University Press, 1996, ISBN 0195092147.
• Eve Curie, Madame Curie: A Biography, translated by Vincent Sheean, Da Capo Press, 2001, ISBN 0306810387.
• Susan Quinn, Marie Curie: A Life, New York, Simon and Schuster, 1995, ISBN 0-671-67542-7.
• Françoise Giroud, Marie Curie: A Life, translated by Lydia Davis, Holmes & Meier, 1986, ASIN B000TOOU7Q.
• Redniss, Lauren, Radioactive, Marie & Pierre Curie: A Tale of Love and Fallout, New York, Harper Collins, 2010, ISBN 9780061351327.

Fiction

• Olov Enquist, Per (2006). The Book about Blanche and Marie. New York: Overlook. ISBN 1-58567-668-3 A 2004 novel by Per Olov Enquist featuring Maria Skłodowska-Curie, neurologist Jean-Martin Charcot, and his Salpêtrière patient "Blanche" (Marie Wittman). The English translation was published in 2006.

Pierre Curie

Pierre Curie (15 May 1859 – 19 April 1906) was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity, and Nobel laureate. He was the son of Dr. Eugène Curie (August 28, 1827 – February 25, 1910) and Sophie-Claire Depouilly Curie (January 15, 1832 – September 27, 1897). In 1903 he received the Nobel Prize in Physics with his wife, Maria Salomea Skłodowska-Curie, and Henri Becquerel, "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel".

Early years

Born in Paris, France, Pierre was educated by his father, Eugène (August 28, 1827 – February 25, 1910), and in his early teens showed a strong aptitude for mathematics and geometry. By the age of 18 he had completed the equivalent of a higher degree, but did not proceed immediately to a doctorate due to lack of money. Instead he worked as a laboratory instructor.

In 1880, Pierre and his older brother Jacques (1856–1941) demonstrated that an electric potential was generated when crystals were compressed, i.e. piezoelectricity. Shortly afterwards, in 1881, they demonstrated the reverse effect: that crystals could be made to deform when subject to an electric field. Almost all digital electronic circuits now rely on this phenomenon in the form of crystal oscillators.

Research

Prior to his famous doctoral studies on magnetism, he designed and perfected an extremely sensitive torsion balance for measuring magnetic coefficients. Variations on this equipment were commonly used by future workers in that area. Pierre Curie studied ferromagnetism, paramagnetism, and diamagnetism for his doctoral thesis, and discovered the effect of temperature on paramagnetism which is now known as Curie's law. The material constant in Curie's law is known as the Curie constant. He also discovered that ferromagnetic substances exhibited a critical temperature transition, above which the substances lost their ferromagnetic behavior. This is now known as the Curie point.

Pierre formulated what is now known as the Curie Dissymmetry Principle: a physical effect cannot have a dissymmetry absent from its efficient cause. For example, a random mixture of sand in zero gravity has no dissymmetry (it is isotropic). Introduce a gravitational field, then there is a dissymmetry because of the direction of the field. Then the sand grains can ‘self-sort’ with the density increasing with depth. But this new arrangement, with the directional arrangement of sand grains, actually reflects the dissymmetry of the gravitational field that causes the separation.

Pierre worked with his wife Marie Curie in isolating polonium and radium. They were the first to use the term "radioactivity", and were pioneers in its study. Their work, including Marie's celebrated doctoral work, made use of a sensitive piezoelectric electrometer constructed by Pierre and his brother Jacques.

Pierre and one of his students made the first discovery of nuclear energy, by identifying the continuous emission of heat from radium particles. He also investigated the radiation emissions of radioactive substances, and through the use of magnetic fields was able to show that some of the emissions were positively charged, some were negative and some were neutral. These correspond to alpha, beta and gamma radiation.

The curie is a unit of radioactivity (3.7 x 10¹⁰ decays per second or 37 gigabecquerels) originally named in honor of Curie by the Radiology Congress in 1910, after his death. Subsequently, there has been some controversy over whether the naming was in honor of Pierre, Marie, or both.

Personal life

Pierre and Marie Curie's daughter Irène Joliot-Curie and their son-in-law Frédéric Joliot-Curie were also physicists involved in the study of radioactivity. They also were awarded a Nobel prize for their work.

The Curies' other daughter, Ève, wrote a noted biography of her mother.

Their granddaughter Hélène Langevin-Joliot is a professor of nuclear physics at the University of Paris, and their grandson Pierre Joliot, who was named after Pierre Curie, is a noted biochemist.

Pierre died in Paris on 19 April 1906. He tried to run across the street while it was raining, but he slipped, and then was hit and run over by a horse drawn vehicle. His skull was badly fractured.

In April 1995 Pierre and Marie were enshrined in the crypt of the Panthéon in Paris.

Awards

• Nobel Prize in Physics (1903)
• Davy Medal (1903)
• Matteucci Medal (1904)
• Elliott Cresson Medal (1909) awarded posthumously during Marie Curie's award ceremony

Polonium

Polonium (pron. /pɵˈloʊniəm/ ) is a chemical element with the symbol Po and atomic number 84, discovered in 1898 by Marie Skłodowska-Curie and Pierre Curie. A rare and highly radioactive element, polonium is chemically similar to bismuth and tellurium, and it occurs in uranium ores. Polonium has been studied for possible use in heating spacecraft. As it is unstable, all isotopes of polonium are radioactive. There is disagreement as to whether polonium is a post-transition metal or metalloid.

Characteristics

Isotopes

Polonium has 33 known isotopes, all of which are radioactive. They have atomic masses that range from 188 to 220 u. ²¹⁰Po (half-life 138.376 days) is the most widely available. ²⁰⁹Po (half-life 103 years) and ²⁰⁸Po (half-life 2.9 years) can be made through the alpha, proton, or deuteron bombardment of lead or bismuth in a cyclotron.

²¹⁰Po is an alpha emitter that has a half-life of 138.376 days; it decays directly to its stable daughter isotope, ²⁰⁶Pb. A milligram of ²¹⁰Po emits about as many alpha particles per second as 4.5 grams of ²²⁶Ra. A few curies (1 curie equals 37 gigabecquerels, 1 Ci = 37 GBq) of ²¹⁰Po emit a blue glow which is caused by excitation of surrounding air. A single gram of ²¹⁰Po generates 140 watts of power. Because it emits many alpha particles, which are stopped within a very short distance in dense media and release their energy, ²¹⁰Po has been used as a lightweight heat source to power thermoelectric cells in artificial satellites; for instance, ²¹⁰Po heat source was also used in each of the Lunokhod rovers deployed on the surface of the Moon, to keep their internal components warm during the lunar nights. Some anti-static brushes contain up to 500 microcuries (20 MBq) of ²¹⁰Po as a source of charged particles for neutralizing static electricity in materials like photographic film.

About one in 100,000 alpha emissions causes an excitation in the nucleus which then results in the emission of a gamma ray. Because of its relatively high rate of alpha emissions, only about 1 in 100,000 result in releasing a gamma ray. But it is the alpha particles, not the side effect of an occasional gamma ray, that results in ²¹⁰Po decay. Low gamma output renders gamma detection nearly impossible, with any emitted gamma nearly indistinguishable from background radiation. At 4.001 u, the alpha particle is too massive to penetrate most barriers, including intact human epidermis. If the skin is broken however, or the alpha emitter is ingested or inhaled, the high charge on the alpha particle will result in severe cellular damage. The high alpha decay of polonium renders alpha detection as the preferred method of quantifying this isotope in the laboratory.

Solid state form

Polonium is a radioactive element that exists in two metallic allotropes. The alpha form has a simple cubic crystal structure with an edge length of 335.2 picometres; the beta form is rhombohedral. The structure of polonium has been characterized by X-ray diffraction and electron diffraction.

²¹⁰Po (in common with ²³⁸Pu) has the ability to become airborne with ease: if a sample is heated in air to 55 °C (131 °F), 50% of it is vaporized in 45 hours, even though the melting point of polonium is 254 °C (489 °F) and its boiling point is 962 °C (1763 °F). More than one hypothesis exists for how polonium does this; one suggestion is that small clusters of polonium atoms are spalled off by the alpha decay.

Chemistry

The chemistry of polonium is similar to that of tellurium and bismuth. Polonium dissolves readily in dilute acids, but is only slightly soluble in alkalis. The hydrogen compound PoH₂ is liquid at room temperature (melting point −36.1°C, boiling point 35.3°C). Halides of the structure PoX₂, PoX₄ and PoX₆ are known. The two oxides PoO₂ and PoO₃ are the products of oxidation of polonium.

It has been reported that some microbes can methylate polonium by the action of methylcobalamin. This is similar to the way in which mercury, selenium and tellurium are methylated in living things to create organometallic compounds. As a result when considering the biochemistry of polonium one should consider the possibility that the polonium will follow the same biochemical pathways as selenium and tellurium.

Compounds

Polonium has no common compounds, only synthetically created ones.

Oxides

• PoO₂
• PoO₃

Hydrides

• PoH₂

Halogen Compounds

• PoX₂, e.g. polonium dichloride, PoCl₂
• PoX₄
• PoX₆

History

Also tentatively called "Radium F", polonium was discovered by Marie Skłodowska-Curie and her husband Pierre Curie in 1898 and was later named after Marie Curie's native land of Poland (Latin: Polonia) Poland at the time was under Russian, Prussian, and Austrian partition, and did not exist as an independent country. It was Curie's hope that naming the element after her native land would publicize its lack of independence. Polonium may be the first element named to highlight a political controversy.

This element was the first one discovered by the Curies while they were investigating the cause of pitchblende radioactivity. The pitchblende, after removal of the radioactive elements uranium and thorium, was more radioactive than both the uranium and thorium put together. This spurred the Curies on to find additional radioactive elements. The Curies first separated out polonium from the pitchblende, and then within a few years, also isolated radium.

Because of the small quantities present in nature, isolation of polonium from natural sources is complicated. The largest ever isolated batch from 37 tonnes of residues from radium production yielded only 40 Ci of polonium-210.

Detection

Gamma counting

By means of radiometric methods such as gamma spectroscopy (or a method using a chemical separation followed by an activity measurement with a non-energy-dispersive counter), it is possible to measure the concentrations of radioisotopes and to distinguish one from another. In practice, background noise would be present and depending on the detector, the line width would be larger which would make it harder to identify and measure the isotope. In biological/medical work it is common to use the natural ⁴⁰K present in all tissues/body fluids as a check of the equipment and as an internal standard.

Alpha counting

The best way to test for (and measure) many alpha emitters is to use alpha-particle spectroscopy as it is common to place a drop of the test solution on a metal disk which is then dried out to give a uniform coating on the disk. This is then used as the test sample. If the thickness of the layer formed on the disk is too thick then the lines of the spectrum are broadened, this is because some of the energy of the alpha particles is lost during their movement through the layer of active material. An alternative method is to use internal liquid scintillation where the sample is mixed with a scintillation cocktail. When the light emitted is then counted, some machines will record the amount of light energy per radioactive decay event. Due to the imperfections of the liquid scintillation method (such as a failure for all the photons to be detected, cloudy or coloured samples can be difficult to count) and the fact that random quenching can reduce the number of photons generated per radioactive decay it is possible to get a broadening of the alpha spectra obtained through liquid scintillation. It is likely that these liquid scintillation spectra will be subject to a Gaussian broadening rather than the distortion exhibited when the layer of active material on a disk is too thick.

A third energy dispersive method for counting alpha particles is to use a semiconductor detector.

From left to right the peaks are due to ²⁰⁹Po, ²¹⁰Po, ²³⁹Pu and ²⁴¹Am. The fact that isotopes such as ²³⁹Pu and ²⁴¹Am have more than one alpha line indicates that the nucleus has the ability to be in different discrete energy levels (like a molecule can).

Occurrence and production

Polonium is a very rare element in nature because of the short half-life of all its isotopes. It is found in uranium ores at about 100 micrograms per metric ton (1 part in 10¹⁰), which is approximately 0.2% of the abundance of radium. The amounts in the Earth's crust are not harmful. Polonium has been found in tobacco smoke from tobacco leaves grown with phosphate fertilizers.

Neutron capture

Synthesis by (n,γ) reaction

In 1934 an experiment showed that when natural ²⁰⁹Bi is bombarded with neutrons, ²¹⁰Bi is created, which then decays to ²¹⁰Po via β decay. The final purification is done pyrochemically followed by liquid-liquid extraction techniques. Polonium may now be made in milligram amounts in this procedure which uses high neutron fluxes found in nuclear reactors. Only about 100 grams are produced each year, practically all of it in Russia, making polonium exceedingly rare.

Proton capture

Synthesis by (p,n) and (p,2n) reactions

It has been found that the longer-lived isotopes of polonium can be formed by proton bombardment of bismuth using a cyclotron. Other more neutron rich isotopes can be formed by the irradiation of platinum with carbon nuclei.

Applications

When it is mixed or alloyed with beryllium, polonium can be a neutron source: beryllium releases a neutron upon absorption of an alpha particle that is supplied by ²¹⁰Po. It has been used in this capacity as a neutron trigger or initiator for nuclear weapons. However, a license is needed to own and operate this form of neutron source. Other uses include the following:

• Devices that eliminate static charges in textile mills and other places. However, beta particle sources are more commonly used and are less dangerous. A non-radioactive alternative is to use a high-voltage DC power supply to ionise air positively or negatively as required.
• ²¹⁰Po can be used as an atomic heat source to power radioisotope thermoelectric generators via thermoelectric materials.
• Because of its very high toxicity, polonium can be used as a poison (for example Alexander Litvinenko poisoning in 2006).
• Polonium is also used to eliminate dust on film.

Toxicity

Overview

By mass, polonium-210 is around 250,000 times more toxic than hydrogen cyanide (the actual LD₅₀ for ²¹⁰Po is about 1 microgram for an 80 kg person (see below) compared with about 250 milligrams for hydrogen cyanide). The main hazard is its intense radioactivity (as an alpha emitter), which makes it very difficult to handle safely: one gram of Po will self-heat to a temperature of around 500 °C (932 °F). Even in microgram amounts, handling ²¹⁰Po is extremely dangerous, requiring specialized equipment and strict handling procedures. Alpha particles emitted by polonium will damage organic tissue easily if polonium is ingested, inhaled, or absorbed, although they do not penetrate the epidermis and hence are not hazardous if the polonium is outside the body.

Acute effects

The median lethal dose (LD₅₀) for acute radiation exposure is generally about 4.5 Sv. The committed effective dose equivalent ²¹⁰Po is 0.51 µSv/Bq if ingested, and 2.5 µSv/Bq if inhaled. Since ²¹⁰Po has an activity of 166 TBq per gram (4,500 Ci/g) (1 gram produces 166×10¹² decays per second), a fatal 4.5 Sv (J/kg) dose can be caused by ingesting 8.8 MBq (238 microcuries, µCi), about 50 nanograms (ng), or inhaling 1.8 MBq (48 µCi), about 10 ng. One gram of ²¹⁰Po could thus in theory poison 20 million people of whom 10 million would die. The actual toxicity of ²¹⁰Po is lower than these estimates, because radiation exposure that is spread out over several weeks (the biological half-life of polonium in humans is 30 to 50 days) is somewhat less damaging than an instantaneous dose. It has been estimated that a median lethal dose of ²¹⁰Po is 0.015 GBq (0.4 mCi), or 0.089 micrograms, still an extremely small amount.

Long term (chronic) effects

In addition to the acute effects, radiation exposure (both internal and external) carries a long-term risk of death from cancer of 5–10% per Sv. The general population is exposed to small amounts of polonium as a radon daughter in indoor air; the isotopes ²¹⁴Po and ²¹⁸Po are thought to cause the majority of the estimated 15,000-22,000 lung cancer deaths in the US every year that have been attributed to indoor radon. Tobacco smoking causes additional exposure to polonium.

Regulatory exposure limits

The maximum allowable body burden for ingested ²¹⁰Po is only 1.1 kBq (30 nCi), which is equivalent to a particle massing only 6.8 picograms. The maximum permissible workplace concentration of airborne ²¹⁰Po is about 10 Bq/m³ (3 × 10⁻¹⁰ µCi/cm³). The target organs for polonium in humans are the spleen and liver. As the spleen (150 g) and the liver (1.3 to 3 kg) are much smaller than the rest of the body, if the polonium is concentrated in these vital organs, it is a greater threat to life than the dose which would be suffered (on average) by the whole body if it were spread evenly throughout the body, in the same way as caesium or tritium (as T₂O).

²¹⁰Po is widely used in industry, and readily available with little regulation or restriction. In the US, a tracking system run by the Nuclear Regulatory Commission will be implemented in 2007 to register purchases of more than 16 curies (590 GBq) of polonium 210 (enough to make up 5,000 lethal doses). The IAEA "is said to be considering tighter regulations... There is talk that it might tighten the polonium reporting requirement by a factor of 10, to 1.6 curies (59 GBq)."

Famous poisoning cases

Notably, the murder of Alexander Litvinenko, a Russian dissident, in 2006 was announced as due to ²¹⁰Po poisoning. According to Prof. Nick Priest of Middlesex University, an environmental toxicologist and radiation expert, speaking on Sky News on December 2, Litvinenko was probably the first person ever to die of the acute α-radiation effects of ²¹⁰Po.

It has also been suggested that Irène Joliot-Curie was the first person ever to die from the radiation effects of polonium (due to a single intake) in 1956. She was accidentally exposed to polonium in 1946 when a sealed capsule of the element exploded on her laboratory bench. A decade later, on 17 March 1956, she died in Paris from leukemia which may have been caused by that exposure.

According to the book The Bomb in the Basement, several death cases in Israel during 1957-1969 were caused by ²¹⁰Po. A leak was discovered at a Weizmann Institute laboratory in 1957. Traces of ²¹⁰Po were found on the hands of professor Dror Sadeh, a physicist who researched radioactive materials. Medical tests indicated no harm, but the tests did not include bone marrow. Sadeh died from cancer. One of his students died of leukemia, and two colleagues died after a few years, both from cancer. The issue was investigated secretly, and there was never any formal admission that a connection between the leak and the deaths had existed.

Treatment

It has been suggested that chelation agents such as British Anti-Lewisite (dimercaprol) can be used to decontaminate humans. In one experiment, rats were given a fatal dose of 1.45 MBq/kg (8.7 ng/kg) of ²¹⁰Po; all untreated rats were dead after 44 days, but 90% of the rats treated with the chelation agent HOEtTTC remained alive after 5 months.

Commercial products containing polonium

Potentially lethal amounts of polonium are present in anti-static brushes sold to photographers. Static eliminator modules with 500 µCi (20 MBq) of polonium are available. In USA, the devices with no more than 500 µCi of (sealed) ²¹⁰Po per unit can be bought in any amount under a "general license", which means that a buyer need not be registered by any authorities.

Tiny amounts of such radioisotopes are sometimes used in the laboratory and for teaching purposes—typically of the order of 4–40 kBq (0.1–1.0 µCi), in the form of sealed sources, with the polonium deposited on a substrate or in a resin or polymer matrix—are often exempt from licensing by the NRC and similar authorities as they are not considered hazardous. Small amounts of ²¹⁰Po are manufactured for sale to the public in the United States as 'needle sources' for laboratory experimentation, and are retailed by scientific supply companies. The actual polonium is a layer of plating which in turn is plated with a material such as gold. This allows the alpha radiation (used in experiments such as cloud chambers) while preventing the polonium from being released and presenting a toxic hazard. According to United Nuclear, they typically sell between four and eight sources per year.

Tobacco

The presence of polonium in tobacco smoke has been known since the early 1960s. Some of the world's biggest tobacco firms researched ways to remove the substance—to no avail—over a 40-year period but never published the results.

Radioactive polonium-210 contained in phosphate fertilizers is absorbed by the roots of plants (such as tobacco) and stored in its tissues. Tobacco plants fertilized by rock phosphates contain polonium-210, which emits alpha radiation estimated to cause about 11,700 lung cancer deaths annually worldwide.

Food

Polonium is also found in the food chain, especially in seafood.

Radium

Radium (pron. /ˈreɪdiəm/) is a chemical element with atomic number 88, represented by symbol Ra. It is an almost pure white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope of radium-226, which has a half-life of 1601 years and decays into radon gas. Due to such instability, radium is luminescent; it gives off a faint blue color.

Radium, in the form of radium chloride, was discovered by Marie Skłodowska-Curie and Pierre Curie in 1898. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Curie and André-Louis Debierne through the electrolysis of radium chloride in 1910. Since its discovery, it has given names like radium A and radium C₂ to several isotopes of other elements that are decay products of radium-226.

In nature, radium is found in uranium ores in trace amounts as small as a seventh of a gram per tonne of uraninite. Radium is not necessary for living organisms and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity.

Characteristics

Physical characteristics

Although radium is not as well studied as its stable lighter homologue barium, the two elements have very similar properties. Their first two ionization energies are very similar: 509.3 and 979.0 kJ·mol⁻¹ for radium and 502.9 and 965.2 kJ·mol⁻¹ for barium. Such low figures yield both elements' high reactivity and the formation of the very stable Ra²⁺ ion and similar Ba²⁺.

Pure radium is a white silvery solid metal, melting at 700 °C (1292 °F), and boiling at 1737 °C (3159 °F), also very close to those of barium. Radium has density of 5.5 g•cm⁻³; radium—barium density ratio is comparable to radium—barium atomic mass ratio, as these elements have very similar body-centered cubic structures.

Chemical characteristics and compounds

Radium is the heaviest alkaline earth metal; its chemical properties mostly resemble those of barium. When exposed to air, radium reacts violently with it, forming radium nitride, which causes blackening of this white metal. It exhibits only +2 oxidation state in solution. Radium ions do not form complexes easily, due to highly basic character of ions. Most radium compounds coprecipitate with all barium, most strontium and most lead compounds, and are ionic salts. Radium ion is colorless, making radium salts white when freshly prepared, turning yellow and ultimately dark with age owing to self-decomposition from the alpha radiation. Compounds of radium flame red-purple and give a characteristic spectrum. Like other alkaline earth metals, radium reacts violently with water and oil to form radium hydroxide and is slightly more volatile than barium, which leads to lesser solubility of radium compounds compared to those of corresponding barium ones. Due to its geologically short half-life and intense radioactivity, radium compounds are quite rare, occurring almost exclusively in uranium ores.

Radium chloride, radium bromide, radium hydroxide and radium nitrate are soluble in water, with solubility of slightly lower than that of barium analog for bromide and chloride and higher for nitrate. Radium hydroxide is the more soluble than hydroxide of other alkaline earth metals, actinium and thorium and more basic than barium hydroxide. It can be separated from these elements by their precipitation with ammonia. Out of insoluble radium compounds, radium sulfate, radium chromate, radium iodate, radium carbonate and radium tetrafluoroberyllate are characterized. Radium oxide, however, remains uncharacterized, despite that other alkaline earth metals oxides are common compounds for corresponding metals.

Isotopes

Radium (Ra) has 25 different known isotopes, four of which are found in nature, with ²²⁶Ra being the most common. ²²³Ra, ²²⁴Ra, ²²⁶Ra and ²²⁸Ra are all generated naturally in the decay of either Uranium (U) or Thorium (Th). ²²⁶Ra is a product of ²³⁸U decay, and is the longest-lived isotope of radium with a half-life of 1601 years; next longest is ²²⁸Ra, a product of ²³²Th breakdown, with a half-life of 5.75 years.

Radium has no stable isotopes; however, four isotopes of radium are present in decay chains, having atomic masses of 223, 224, 226 and 228, all of which present in trace amounts. The most abundant and the longest-living one is radium-226, with half-life of 1601 years. To date, 33 isotopes of radium have been synthesized, ranging in mass number from 202 to 234.

To date, at least 12 nuclear isomers have been reported; the most stable of them is radium-205m, with half-life of between 130 and 230 milliseconds. All ground states of isotopes from radium-205 to radium-214 and from radium-221 to radium-234 have longer ones.

Three other natural radio isotopes have received historical names in early twentieth century: radium-223 was known as actinium X, radium-224 as thorium X and radium-228 as mesothorium I. Radium-226 has given historical names to its decay products after the whole element, such as radium A for polonium-218.

Radioactivity

Radium is over one million times more radioactive than the same mass of uranium. Its decay occurs in at least seven stages; the successive main products have been studied and were called radium emanation or exradio (now identified as radon), radium A (polonium), radium B (lead), radium C (bismuth), etc. Radon is a heavy gas and the later products are solids. These products are themselves radioactive elements, each with an atomic weight a little lower than its predecessor.

Radium loses about 1% of its activity in 25 years, being transformed into elements of lower atomic weight with lead being the final product of disintegration.

The SI unit of radioactivity is the becquerel (Bq), equal to one disintegration per second. The Curie is a non-SI unit defined as that amount of radioactivity which has the same disintegration rate as 1 gram of Ra-226 (3.7 x 10¹⁰ disintegrations per second, or 37 GBq).

Radium metal maintains itself at a higher temperature than its surroundings because of the radiation it emits - alpha particles, beta particles, and gamma rays. More specifically, the alpha particles are produced by the radium decay, whereas the beta particles and gamma rays are produced by relatively short half-life elements further down the decay chain.

Occurrence

Radium is a decay product of uranium and is therefore found in all uranium-bearing ores. (One ton of pitchblende typically yields about one seventh of a gram of radium). Radium was originally acquired from pitchblende ore from Joachimsthal, Bohemia, in the Czech Republic. Carnotite sands in Colorado provide some of the element, but richer ores are found in the Democratic Republic of the Congo and the Great Lakes area of Canada, and can also be extracted from uranium processing waste. Large radium-containing uranium deposits are located in Canada (Ontario), the United States (New Mexico, Utah, and Virginia), Australia, and in other places.

Production

All radium occurring today is produced by decay of heavier elements, being present in decay chains. Due to such short half-lives of isotopes, radium is not primordial but trace. It cannot occur in big quantities due to both isotopes of radium have short half-lives and parents nuclides have very long ones. Radium is found in tiny quantities in the uranium ore uraninite, and various other uranium minerals and in even tinier quantities in thorium ones.

History

Summary of radium decay products that used to have 'radium' word in their historical names

Historic name	Symbol, present name
Radium emanation	222Rn, radon-222
Radium A	218Po, polonium-218
Radium C	214Bi, bismuth-214
Radium C1	214Po, polonium-214
Radium C2	210Tl, thallium-210
Radium D	210Pb, lead-210
Radium E	210Bi, bismuth-210
Radium F	210Po, polonium-210

Radium (Latin radius, ray) was discovered by Marie Skłodowska-Curie and her husband Pierre on December 21, 1898 in uraninite sample. While studying the mineral, the Curies removed uranium from it and found that the remaining material was still radioactive. They then separated out a radioactive mixture consisting mostly of barium which gave a brilliant green flame color and crimson carmine spectral lines which had never been documented before. The Curies announced their discovery to the French Academy of Sciences on December 26, 1898. The naming of Radium dates to circa 1899, from French 'Radium', formed in Modern Latin from radius 'ray', called for its power of emitting energy in the form of rays. In 1910, radium was isolated as a pure metal by Curie and André-Louis Debierne through the electrolysis of a pure radium chloride solution by using a mercury cathode and distilling in an atmosphere of hydrogen gas. New Curies' element was first industrially produced at the beginning of the 20th century by Biraco, a subsidiary company of Union Minière du Haut Katanga (UMHK) in its Olen plant in Belgium. UMHK offered to Marie Curie her first gramme of radium. It gave historical names the decay products of radium, such as radium A, B, C, etc, now known to be isotopes of other elements.

On February 4, 1936 radium E (bismuth-210) became the first radioactive element to be made synthetically in the United States. Dr. John Jacob Livingood at the radiation lab at University of California, Berkeley was bombarding several elements with 5-MEV deuterons. He noted that irradiated bismuth emits fast electrons with a 5-day half-life, which matched the behavior of radium E.

The common historical unit for radioactivity, curie, is based on the radioactivity of ²²⁶Ra.

Applications

Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered radioisotopes, such as ⁶⁰Co and ¹³⁷Cs, are replacing radium in even these limited uses because several of these isotopes are more powerful emitters, safer to handle, and available in more concentrated form.

When mixed with beryllium, it is a neutron source for physics experiments.

Historical uses

Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. In the mid-1920s, a lawsuit was filed by five dying "Radium Girl" dial painters who had painted radium-based luminous paints on the dials of watches and clocks. The dial painters' exposure to radium caused serious health effects which included sores, anemia and bone cancer. This is because radium is treated as calcium by the body, and deposited in the bones, where radioactivity degrades marrow and can mutate bone cells.

During the litigation, it was determined that company scientists and management had taken considerable precautions to protect themselves from the effects of radiation, yet had not seen fit to protect their employees. Worse, for several years, the companies had attempted to cover up the effects and avoid liability by insisting that the Radium Girls were instead suffering from syphilis. This complete disregard for employee welfare had a significant impact on the formulation of occupational disease labor law.

As a result of the lawsuit, the adverse effects of radioactivity became widely known, and radium dial painters were instructed in proper safety precautions and provided with protective gear. In particular, dial painters no longer shaped paint brushes by lip. Radium was still used in dials as late as the 1960s, but there were no further injuries to dial painters. This further highlighted that the plight of the Radium Girls was completely preventable.

After the 1960s, radium paint was first replaced with promethium paint, and later by tritium bottles which continue to be used today. Although the beta radiation from tritium is potentially dangerous if ingested, it has replaced radium in these applications.

Radium was once an additive in products like toothpaste, hair creams, and even food items due to its supposed curative powers. Such products soon fell out of vogue and were prohibited by authorities in many countries, after it was discovered they could have serious adverse health effects. (See for instance Radithor or Revigator types of "Radium water" or "Standard Radium Solution for Drinking") Spas featuring radium-rich water are still occasionally touted as beneficial, such as those in Misasa, Tottori, Japan. In the U.S., nasal radium irradiation was also administered to children to prevent middle ear problems or enlarged tonsils from the late 1940s through early 1970s.

In 1909, the famous Rutherford experiment used radium as an alpha source to probe the atomic structure of gold. This experiment led to the Rutherford model of the atom and revolutionized the field of nuclear physics.

Radium (usually in the form of radium chloride) was used in medicine to produce radon gas which in turn is used as a cancer treatment, for example several of these radon sources were used in Canada in the 1920s and 1930s. The isotope ²²³Ra is currently under investigation for use in medicine as cancer treatment of bone metastasis.

Precautions

Radium is highly radioactive and its decay product, radon gas, is also radioactive. Since radium is chemically similar to calcium, it has the potential to cause great harm by replacing calcium in bones. Exposure to radium can cause cancer and other disorders, because radium and its decay product radon emit alpha particles upon their decay, which kill and mutate cells. The effects of radiation at the time of radium's discovery were not well characterized, however, and thus some scientists carried vials of radium in their pockets, only to find that they had chemical burns at the place where they put their vials the next day. Handling of radium has also been blamed for Marie Curie's death due to aplastic anemia. Therefore, stored radium should be ventilated to prevent accumulation of radon.

Emitted energy from the decay of radium also ionizes gases, affects photographic plates, and produces many other detrimental effects - to the extent that at the time of the Manhattan Project in 1944, the "tolerance dose" for workers was set at 0.1 microgram of ingested radium.

Further reading

• Macklis, R. M. (1993). "The great radium scandal". Scientific American 269 (2): 94–99. doi:10.1038/scientificamerican0893-94.
• Clark, Claudia (1987). Radium Girls: Women and Industrial Health Reform, 1910–1935. University of North Carolina Press. ISBN 0-8078-4640-6

References

Notes

• Albert Stwertka (1998). Guide to the Elements - Revised Edition. Oxford University Press. ISBN 0-19-508083-1
• Denise Grady (October 6, 1998). "A Glow in the Dark, and a Lesson in Scientific Peril". The New York Times. Retrieved 2007-12-25.
• Nanny Fröman,"Marie and Pierre Curie and the Discovery of Polonium and Radium", Nobel Foundation, 1 December 1996, retrieved 2007-12-25

Ève Curie

Ève Denise Curie Labouisse (December 6, 1904 – October 22, 2007) was a French-American writer, journalist and pianist. Ève Curie was the younger daughter of Marie Curie and Pierre Curie. Her sister was Irène Joliot-Curie and her brother-in-law Frédéric Joliot-Curie. Ève was the only member of her family who did not choose a career as a scientist and did not win a Nobel Prize, although her husband Henry Richardson Labouisse, Jr. did collect the Nobel Peace Price in 1965 on behalf of UNICEF. She worked as a journalist and authored her mother's biography Madame Curie and a book of war reportage, Journey Among Warriors. From the 1960s she committed herself to work for UNICEF, providing help to children and mothers in developing countries.

Childhood

Ève Denise Curie was born in Paris, France on December 6, 1904. She was the younger daughter of the scientists Marie and Pierre Curie, who also had another daughter Irène (born 1897). Ève virtually did not know her father, who died tragically in 1906 in an accident, run over by a horse cart. After this accident, Marie Curie and her daughters were supported for some time by their paternal grandfather Dr. Eugène Curie. When he died in 1910, Marie Curie was forced to bring up her daughters herself with the help of governesses. Even though Ève confessed later that as a child she had suffered from a lack of sufficient attention of her mother and that only later, in her teens, she developed a stronger emotional bond to her, Marie took great care for the education and development of interests of both her daughters. Whereas Irène followed in her mother's footsteps and became an eminent scientist (she was awarded the Nobel Prize in Chemistry with her husband Frédéric Joliot-Curie in 1935), Ève showed more artistic and literary interests. Even as a child she displayed a particular talent for music.

Marie Curie also took care of the physical development of the girls. Whatever the weather, they went on long walks and rode on bikes. They went swimming in summer, and Marie had gymnastics equipment installed in the garden of their house in Sceaux, Hauts-de-Seine. Ève and Irène also learned sewing, gardening and cooking.

Although the girls were French nationals (Ève became later an American citizen), and their first language was French, they were familiar with their Polish origin and spoke Polish. In 1911 they visited Poland, which was then under Russian rule. The main purpose of the visit was to visit with Bronisława Skłodowska, Marie's sister, who was staying in a sanatorium at the time. During their visit to Poland, they also rode horses and hiked in the mountains.

Youth

In 1921, 16-year-old Ève set off on her first journey across the Atlantic Ocean: that spring, she sailed with her sister and mother on board the ship RMS Olympic to New York City. Marie Curie, as a two-time laureate of the Nobel Prize, the discoverer of radium and polonium, was welcomed there with all due ceremony; her daughters were also very popular with American high society. Radiant at parties and joyous, Ève was dubbed by the press "the girl with radium eyes". During the trip Ève and Irène also acted as their mother's "bodyguards" – Marie, usually focused on research work and preferring a simple life, did not always feel comfortable facing the homage paid to her. While in the United States, Marie, Irène and Ève met President Warren G. Harding in Washington, D.C., saw the Niagara Falls and went by train to see the Grand Canyon. They returned to Paris in June 1921.

Ève, like her sister Irène, graduated from the Collège Sévigné in Paris, where she obtained two bachelor's degrees, in Science and Philosophy, in 1925. Meanwhile, she also improved her piano skills and gave her first concert in Paris in 1925. Later, she performed on stage many times, giving concerts in the French capital, in the provinces and in Belgium.

After Irène married Frédéric Joliot in 1926, Ève stayed with her mother in Paris, taking care of her and accompanying her on trips throughout France, Italy, Belgium, and Switzerland. In 1932, they also accompanied President of Czechoslovakia Tomáš Masaryk on his trip to Spain.

Although she loved her mother, Ève had a quite different personality from her (and from her sister Irène). She was not interested in science, preferring the humanities. Unlike her mother, she was always attracted by refined life. Whereas Marie usually wore simple, black dresses, Ève, with an attractive appearance, always cared about smart clothes, wore high-heeled shoes and make-up, and loved shining at parties. However, both Ève and Irène nursed her mother with devotion until her death. Marie, ill with aplastic anemia, probably caused by her long-term exposure to radium, died on July 4, 1934.

Mother's biography

After Marie Curie's death, Ève decided to give voice to her love for her by writing her biography. To this end, she temporarily withdrew from social life and moved to a small flat in Auteuil, Yvelines, where she gathered and sorted out documents and letters left by Marie. In autumn 1935, she also visited her family in Poland, looking for information about her mother's childhood and youth. The fruit of this work was the biography Madame Curie, simultaneously published in France, Britain, Italy, Spain, the United States and other countries in 1937.

The biography became highly popular instantly upon its publication; in many countries (including the United States) it was a bestseller. The book won the 1937 National Book Award for Fiction, and was adapted for the silver screen in 1943 by Metro-Goldwyn-Mayer, with Greer Garson in the title role.

In later years, however, Marie Curie's biography often met with criticism of science historians, who accused Ève of presenting her mother in an over-sentimental way and failing to mention, for example, Marie's love affair with Paul Langevin, her husband's former student. Langevin was a married man and a father of four; their relationship, established after Pierre Curie's death, caused a great scandal in early twentieth century France. Ève was also accused of not presenting all the troubles and insults her mother had to suffer from French scientific circles and the gutter press.

Ève became more and more engaged in literary and journalistic work. Apart from her mother's biography, she published musical reviews in the Candide weekly and articles on theatre, music and film in other Paris newspapers.

Second World War

After the outbreak of the Second World War in 1939, the novelist and playwright Jean Giraudoux, who had become the French Information Commissioner (Commissaire général à l'information) in the same year, appointed Ève Curie head of the feminine division in his office. After Germany invaded France, Ève left Paris on June 11, 1940, and after the surrender of France she fled with other refugees on board an overcrowded ship to England, which was strafed by German aircraft. There she joined the Free French Forces of General Charles de Gaulle and started her active fight against Nazism, which resulted in the Vichy government's depriving her of French nationality and confiscating her property in 1941.

Ève Curie spent most of the war years in Britain, where she met Winston Churchill, and the United States, where she gave lectures and wrote articles to American newspapers (mostly the New York Herald Tribune. In 1940 she met Eleanor Roosevelt at the White House. Inspired by this visit, she later gave a series of lectures on French Women and the War; in May 1940 The Atlantic Monthly published her essay under the same title.

From November 1941 to April 1942, Ève Curie traveled as a war correspondent to Africa, the Soviet Union and Asia, where she witnessed the British offensive in Egypt and Libya in December 1941 and the Soviet counter-offensive at Moscow in January 1942. During this journey she met the Shah of Iran, Mohammad Reza Pahlavi, the leader of Free China, Chiang Kai-shek, fighting the Japanese, and Mahatma Gandhi. Several times, she also had the opportunity to meet her half-compatriots, Polish soldiers, who fought on the side of the British or organized the Polish Army in the Soviet Union. Curie's reports from this journey were published in American newspapers, and in 1943 they were gathered in the book Journey Among Warriors, which was nominated for the Pulitzer Prize for Correspondence in 1944 (eventually losing to Ernest Taylor Pyle)

After her return to Europe, Ève Curie served as a volunteer in the women's medical corps of the Free French during the Italian Campaign, where she was promoted to the rank of lieutenant in the 1st Armored Division. In August 1944 she took part in landing with her troops in Provence in southern France. She was decorated with the Croix de guerre for her services.

After the war

After the liberation of France, Ève Curie first worked as a co-editor of the daily newspaper Paris-Presse from 1944 to 1949, but was also active in the political sphere. For example, she was responsible for women's affairs in de Gaulle's government, and in 1948 along with other prominent European intellectuals, she appealed to the United Nations for recognition of the state of Israel. In the years 1952-1954, she was a special advisor to Hastings Lionel Ismay, the first Secretary General of NATO. On 19 November 1954 she married the American politician and diplomat Henry Richardson Labouisse, Jr., who served as the United States Ambassador to Greece from 1962 to 1965. Ève Curie became an American citizen in 1958.

Work for UNICEF

In 1965, Ève's husband gave up his job in the U.S. government when the Secretary General of the United Nations U Thant offered him the position of the Executive Director of the United Nations Children's Fund UNICEF. Labouisse held this office till 1979, actively supported by his wife, who also worked for the organization and was often called "the First Lady of UNICEF". Together, they visited more than 100 countries, mostly in the Third World, which were beneficiaries of UNICEF's help. In 1965, Labouisse, accompanied by his wife, accepted the Nobel Peace Prize, which was awarded to his organization.

Last years of life

After her husband's death in 1987, Ève lived in New York City. She had no children from her marriage to Henry Labouisse, and was only visited by her stepdaughter, Anne Peretz (Labouisse's only daughter, born of his first marriage).

In December 2004, Ève Curie's celebrated her one-hundredth birthday. On this occasion, she was visited in her New York flat by the Secretary General of the United Nations Kofi Annan. She also received congratulatory letters from the presidents of the United States – George W. Bush – and France – Jacques Chirac.

In July 2005, Ève Curie Labouisse was promoted for her work in UNICEF to the rank of ‘Officier de la Légion d’Honneur’ of the Republic of France – the country’s highest decoration. She expressed thanks for the decoration, saying:

I feel honoured, I feel proud. I'm a little embarrassed because I don't think I deserve all those wonderful compliments, so I just don't quite know how to behave. But it's a really wonderful day for me and I will remember it for a very long time.

She sometimes joked that she brought shame on her family. "There were five Nobel Prizes in my family," she joked, "two for my mother, one for my father, one for [my] sister and brother-in-law and one for my husband. Only I was not successful…".

Ève Curie died in her sleep on 22 October 2007 in her residence on Sutton Place in Manhattan, aged 102.

Ann Veneman, the Executive Director of UNICEF, said after her death:

Mrs. Labouisse was a talented professional woman who used her many skills to promote peace and development. While her husband headed UNICEF, she played a very active role in the organization, traveling with him to advocate for children and to provide support and encouragement to UNICEF staff in remote and difficult locations. Her energy and her commitment to the betterment of the world should serve as an inspiration to us all.

Irène Joliot-Curie

Irène Joliot-Curie (12 September 1897 – 17 March 1956) was a French scientist, the daughter of Marie Skłodowska-Curie and Pierre Curie and the wife of Frédéric Joliot-Curie. Jointly with her husband, Joliot-Curie was awarded the Nobel Prize for chemistry in 1935 for their discovery of artificial radioactivity. This made the Curies the family with most Nobel laureates to date. Both children of the Joliot-Curies, Hélène and Pierre, are also esteemed scientists.

Biography

Early years

Curie was born in Paris. After a year of traditional education, which began when she was 6 years old, her parents realized her obvious mathematical talent and decided that Irène’s academic abilities needed a more challenging environment. Marie joined forces with a number of eminent French scholars, including the prominent French physicist Paul Langevin to form “The Cooperative,” a private gathering of some of the most distinguished academics in France. Each contributed to educating one another’s children in their respective homes. The curriculum of The Cooperative was varied and included not only the principles of science and scientific research but such diverse subjects as Chinese and sculpture and with great emphasis placed on self expression and play.

This arrangement lasted for two years after which Curie re-entered a more orthodox learning environment at the Collège Sévigné in central Paris from 1912 to 1914 and then onto the Faculty of Science at the Sorbonne, to complete her Baccalaureat. Her studies at the Faculty of Science were interrupted by World War I.

World War I

Initially, Curie was taken by her mother to Brittany, but a year later when she turned 18 she was re-united with her mother, running the 20 mobile field hospitals that Marie had established. The hospitals were equipped with primitive X-ray equipment made possible by the Curies’ radiochemical research. This technology greatly assisted doctors to locate shrapnel in wounded soldiers, but it was crude and led to both Marie and Irène, who were serving as nurse radiographers, to suffer large doses of radiation exposure.

After the War, Curie returned to Paris to study at The Radium Institute, which had been built by her parents. The institute was completed in 1914 but remained empty during the war. Her doctoral thesis was concerned with the alpha rays of polonium, the second element discovered by her parents and named after Marie’s country of birth, Poland. Curie became Doctor of Science in 1925.

Research

As she neared the end of her doctorate in 1924 she was asked to teach the precise laboratory techniques required for radiochemical research to the young chemical engineer Frédéric Joliot whom she would later come to wed.

From 1928 Joliot-Curie and husband Frédéric combined their research interests on the study of atomic nuclei. Though their experiments identified both the positron and the neutron, they failed to interpret the significance of the results and the discoveries were later claimed by C.D. Anderson and James Chadwick respectively. These discoveries would have secured greatness indeed, as together with J. J. Thomson's discovery of the electron in 1897, they finally replaced Dalton’s theory of atoms being solid spherical particles.

Finally, in 1934 they made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre, who had isolated naturally occurring radioactive elements, Joliot-Curies realised the alchemist’s dream of turning one element into another, creating radioactive nitrogen from boron and then radioactive isotopes of phosphorus from aluminium and silicon from magnesium. For example, irradiating the main natural and stable isotope of aluminum with alpha particles (i.e. helium nuclei) results in an unstable isotope of phosphorus : ²⁷Al + ⁴He > ³⁰P + ¹n. By now the application of radioactive materials for use in medicine was growing and this discovery led to an ability to create radioactive materials quickly, cheaply and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Joliot-Curie was awarded a professorship at the Faculty of Science.

Irène’s group pioneered research into radium nuclei that led a separate group of German physicists to discover nuclear fission; the splitting of the nucleus itself and the vast amounts of energy emitted as a result.

The years of working so closely with such deadly materials finally caught up with Joliot-Curie and she was diagnosed with leukemia. She had been accidentally exposed to polonium when a sealed capsule of the element exploded on her laboratory bench in 1946. Treatment with antibiotics and a series of operations did relieve her suffering temporarily but her condition continued to deteriorate. Despite this Joliot-Curie continued to work and in 1955 drew up plans for new physics laboratories at the Université d’Orsay, South of Paris.

Political views

The Joliot-Curies had become increasingly aware of the growth of the fascist movement. They opposed its ideals and joined the Socialist Party in 1934, the Comité de Vigilance des Intellectuels Antifascistes a year later, and in 1936 actively supported the Republicans in the Spanish Civil War. In the same year, Joliot-Curie was appointed Undersecretary of State for Scientific Research for the French government where she helped in founding the Centre National de la Recherche Scientifique.

The Joliot-Curies had continued Pierre and Marie’s policy of publishing all of their work for the benefit of the global scientific community, but afraid of the danger that might result should it be developed for military use, they stopped. On 30 October 1939 they placed all of their documentation on nuclear fission in the vaults of the Académie des Sciences where it remained until 1949.

Joliot-Curie's political career continued after the war and she became a commissioner in the Commissariat à l'énergie Atomique. However, she still found time for scientific work and in 1946 became director of her mother’s Institut du Radium, Radium Institute.

Joliot-Curie became actively involved in promoting women’s education, serving on the National Committee of the Union of French Women (Comité National de l'Union des Femmes Françaises) and the World Peace Council. Joliot-Curies were given memberships to the French Légion d'honneur; Irène as an officer and Frederic as a commissioner, recognising his earlier work for the resistance.

Personal life

Irène and Frédéric hyphenated their surnames to Joliot-Curie after they married in 1926. Eleven months later, their daughter Hélène was born, who would also become a noted physicist. Their son, Pierre, a biologist, was born in 1932.

During World War II Joliot-Curie contracted tuberculosis and was forced to spend several years convalescing in Switzerland. Concern for her own health together with the anguish of leaving her husband and children in occupied France was hard to bear and she did make several dangerous visits back to France, enduring detention by German troops at the Swiss border on more than one occasion. Finally, in 1944 Joliot-Curie judged it too dangerous for her family to remain in France and she took her children back to Switzerland.

In 1956, after a final convalescent period in the French Alps, Joliot-Curie was admitted to the Curie hospital in Paris where she died on 17 March at the age of 58 from leukemia.

Joliot-Curie's daughter, Hélène Langevin-Joliot, is a nuclear physicist and professor at the University of Paris; her son, Pierre Joliot, is a biochemist at Centre National de la Recherche Scientifique.

Curie Institute, Warsaw

The Maria Skłodowska-Curie Institute of Oncology (Polish: Centrum Onkologii – Instytut im. Marii Skłodowskiej-Curie w Warszawie) in Warsaw was founded in 1932 as the Radium Institute by Maria Skłodowska-Curie in collaboration with the Polish Government, especially President Ignacy Mościcki.

After World War II, the Institute changed its name to "Maria Skłodowska-Curie Institute of Oncology".

Today it is a specialized health institute of the Polish Ministry of Health. It also has regional branches in Gliwice and Kraków.

It is the leading and most specialized cancer research and treatment center in Poland.

One of the Institute's brick walls bears the inscription, "MARII SKŁODOWSKIEJ CURIE, W HOŁDZIE" [In homage to Maria Skłodowska-Curie].