CURIES ISOLATE RADIUM:

April 20, 1902

On April 20, 1902, Marie and Pierre Curie successfully isolate radioactive
radium salts from the mineral pitchblende in their laboratory in Paris. In 1898,
the Curies discovered the existence of the elements radium and polonium in their
research of pitchblende. One year after isolating radium, they would share the
1903 Nobel Prize in physics with French scientist A. Henri Becquerel for their
groundbreaking investigations of radioactivity.Marie Curie was born Marie
Sklodowska in Warsaw, Poland, in 1867. The daughter of a physics teacher, she
was a gifted student and in 1891 went to study at the Sorbonne in Paris. With
highest honors, she received a degree in physical sciences in 1893 and in
mathematics in 1894. That year she met Pierre Curie, a noted French physicist
and chemist who had done important work in magnetism. Marie and Pierre married
in 1895, marking the beginning of a scientific partnership that would achieve
world renown.Looking for a subject for her doctoral thesis, Marie Curie began
studying uranium, which was at the heart of Becquerel's discovery of
radioactivity in 1896. The term radioactivity, which describes the phenomenon of
radiation caused by atomic decay, was in fact coined by Marie Curie. In her
husband's laboratory, she studied the mineral pitchblende, of which uranium is
the primary element, and reported the probable existence of one or more other
radioactive elements in the mineral. Pierre Curie joined her in her research,
and in 1898 they discovered polonium, named after Marie's native Poland, and
radium.While Pierre investigated the physical properties of the new elements,
Marie worked to chemically isolate radium from pitchblende. Unlike uranium and
polonium, radium does not occur freely in nature, and Marie and her assistant
Andrý Debierne laboriously refined several tons of pitchblende in order to
isolate one-tenth gram of pure radium chloride in 1902. On the results of this
research, she was awarded her doctorate of science in June 1903 and later in the
year shared the Nobel Prize in physics with her husband and Becquerel. She was
the first woman to win a Nobel Prize.Pierre Curie was appointed to the chair of
physics at the Sorbonne in 1904, and Marie continued her efforts to isolate
pure, non-chloride radium. On April 19, 1906, Pierre Curie was killed in an
accident in the Paris streets. Although devastated, Marie Curie vowed to
continue her work and in May 1906 was appointed to her husband's seat at the
Sorbonne, thus becoming the university's first female professor. In 1910, with
Debierne, she finally succeeded in isolating pure, metallic radium. For this
achievement, she was the sole recipient of the 1911 Nobel Prize in chemistry,
making her the first person to win a second Nobel Prize.She became interested in
the medical applications of radioactive substances, working on radiology during
World War I and the potential of radium as a cancer therapy. Beginning in 1918,
the Radium Institute at the University of Paris began to operate under Curie's
direction and from its inception was a major center for chemistry and nuclear
physics. In 1921, she visited the United States, and President Warren G. Harding
presented her with a gram of radium. Curie's daughter, Irene Curie, was also a
physical chemist and, with her husband, Frederic Joliot, was awarded the 1935
Nobel Prize in chemistry for the discovery of artificial radioactivity. Marie
Curie died in 1934 from leukemia caused by four decades of exposure to
radioactive substances.