Marie CurieMarie Curie(1867-1934) was a French physicist with many accomplishments in both physics and chemistry. Marie and her husband Pierre, who was also a French physicist, are both famous for their work in radioactivity. Marie Curie, originally named Marja Sklodowska, was born in Warsaw, Poland on Nov.7, 1867. Her first learning of physics came from her father who taught it in high school. Marie's father must have taught his daughter well because in 1891, she went to Paris(where she changed her original name) and enrolled in the Sorbonne. Then two years later she passed the Examination for her physics degree ranking in first place. She met Pierre Curie in 1894, and married him in the next year. Marie subsequently gave birth to two daughters Irene(1897) and Eve(1904). Pierre Curie(1859-1906) obtained his doctorate in the year of his marriage, but had already distinguished himself in the study of the properties of crystals. He discovered the phenomenon of piezoelectricity, whereby changes in the volume of certain crystals excite small electric potentials. He discovered that the magnetic susceptibility of paramagnetic materials is inversely proportional to the absolute temperature, and that there exists a critical temperature above which the magnetic properties disappear, this is called the Curie temperature. Marie Curie was interested in the recent discoveries of radiation, which were made by Wilhelm Roentgen on the discovery of X-rays in 1895, and by Henri Becquerel in 1896, when he discovered uranium gives off similar invisible radiation as the X-rays. Curie thus began studying uranium radiation and made it her doctoral thesis. With the aid of an electrometer built by Pierre, Marie measured the strength of the radiation emitted form uranium compounds and found it proportional to the uranium content, constant over a long period of time and influenced by external conditions. She detected a similar immutable radiation in the compounds of thorium. While checking these results, she made the discovery that uranium pitchblende and the mineral chalcolite emitted four times as much radiation as their uranium content. She realized that unknown elements, even more radioactive then uranium must be present. Then in 1898 she drew the revolutionary conclusion that pitchblende contains a small amount of an unknown radiating element. Pierre Curie understood the importance of this supposition and joined his wife's work. In the next year, the Curie's discovered two new radiating elements which they named Polonium(after Maries native country) and Radium. They now began the tedious and monumental task of isolating these elements so that their chemical properties could be determined. During the next four years, working in a leaky wooden shed, they processed a ton of pitchblende, laboriously isolating from it a fraction of a gram of radium.

In 1903, Marie Curie obtained her doctorate for a thesis on radioactive substances, and with her husband and Henri Becquerel she won the Nobel Prize for physics for the joint discovery of radioactivity. Finally, the Curies financial aspect was relieved, and the following year Pierre was made the professor at the Sorbonne, and Marie the assistant. Everything was going well for the Curies, but then Pierre was run over by a horse drawn cart and killed. Marie was deeply affected by his death and overcame this blow only by putting all her energy into her scientific work that they had begun together. Marie took over her husband's post at the Sorbonne, thus making her the first female lecturer at the Sorbonne, and in 1908 she was appointed the professor. In 1911 she received an unprecedented second Nobel prize, this time in chemistry for her work on radium and it's compound. During World War I, Madame Curie dedicated herself entirely to the development of the use of X-rays in medicine. In 1918 she became head of the Paris Institute of Radium, were her daughter Irene Joliot-Curie worked with her husband Fredric Joliet. Her research for the rest of her life was dedicated to the chemistry of radioactive materials and their medical applications. She labored to establish international scholarships and lectured abroad. Marie Curie died on July 4, 1934 of Leukemia, which was undoubtedly caused by prolonged exposure to radiation. A year later Irene and Fredric won the Nobel prize in chemistry for the synthesis of new radioactive elements. ELEMENTS MARIE DISCOVEREDPolonium is a rare metallic element, which naturally occurs in uranium ore pitchblende. But most commonly is made artificially by bombarding bismuth( a brittle metal) with neutrons. It is used chiefly by scientists for nuclear research. Radium is a highly radioactive metallic element. It occurs mostly in thorium ores and uranium. It was discovered by the Curies while processing pitchblende. Until mid-1950's radium was only used for treating cancer and an ingredient in fluorescent paint used for watch and instrument dials. Today safer and cheaper sources of radiation have replaced radium for most industrial and medical uses. CONCLUSIONThe work of the Curies, which by its nature dealt with changes in the atomic nucleus, led the way toward modern understanding of the atom as an entity that can be split to release enormous amounts of energy. With these discoveries we have been able to actually put to use the elements in our everyday life.