Monday, September 13, 2010

Irene Joliot-Curie

Irene Juliot-Curie was born in Paris, France on September 12, 1897, the daughter of nuclear scientists Marie and Pierre Curie. After a year of formal education when she was six, Juliot-Currie's parents joined a group of distinguished French academics called "The Cooperative" which took turns providing instruction for their children. Classes took place at the academic's homes and provided instruction not only on science but diverse subjects such as Chinese and sculpture. After 2 years of this instruction she returned to a more traditional academic setting, attending the College Sevigne for two years. She then went to the Sorbonne, but her studies were interrupted by the outbreak of World War I.

During the war Juliot-Curie helped her mother operating primitive X-ray machines that had been made possible by Marie's research. The machines made it possible to for doctors to locate shrapnel in patients, but the equipment was primitive and she suffered from radiation exposure. After the war she returned to Paris where she worked at her parents' Radium Institute and she completed a doctoral thesis concerning the alpha rays emited by polonium. She was awarded her doctorate in 1925.

While working on her doctorate she was asked to teach the techniques used in radiochemical research to a young chemical engineer named Federic Joliot. They would later marry and share hyphenated last names. Their collaborative study of atomic nuclei was the first to identify the existence of neutrons and positrons, although James Chadwick and C. D. Anderson, respectively, would claim the discoveries. Their breakthrough came in 1934, after bombarding a thin sheet of aluminum with alpha particles, they noticed that the area bombarded gave off positive electrons, after the alpha particles were removed, in such a way that suggested radioactive elements. Further examination of the product revealed that it was a radioactive isotope of phosphorus.

The means of atomic transmution discovered by the Curies involves bombarding nuclei with subatomic particles. The transmutation accomplished by the Curies (aluminum to phosphorus) was accomplished by bombarding aluminum with alpha particles. Alpha particles are low energy radioactive particles that consist of helium nuclei, with two protons and two neutrons. In this case aluminum (atomic number 13) is changed into phosphorus (atomic number 15) by the addition on two protons from an alpha particle. The resulting phosphorus nuclei is unstable and breaks down, releasing positrons.

For their discovery of nuclear transmutation the Curies were awarded the Nobel Prize for chemistry in 1935. Irene Juliot-Curie became only the second woman, after her mother to win the Nobel Prize in chemistry. With the prize came employment including a chair at the Sorbonne. During World War II she contracted tuberculosis and she went to Switzerland to convalesce. She made several trips back to Paris to visit her husband and children and on more than one occasion was detained by German troops. In 1956 she contracted leukemia and she died on March 17, 1956.


Bensaude-Vincent, Bernedette; "Irene Joliot-Curie" in Nobel Laureates in Chemistry, 1901-1992; Chemical Heritage Foundation, 1992

Irene Joliot-Curie Nobel Biography

Irene Joliot-Curie Wikipedia Entry

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