Marie Curie

Major contributions

• Coined the term "radioactivity" and, together with her husband Pierre Curie, conducted foundational research establishing it as a fundamental atomic property rather than a chemical reaction
• Discovered two new chemical elements, polonium (named after her native Poland) and radium, isolating them from tonnes of pitchblende ore through years of painstaking manual processing
• Developed techniques for isolating radioactive isotopes and for precisely measuring radioactivity, establishing much of the early experimental methodology for the field
• Championed the use of mobile x-ray units ("petites Curies") during World War I, personally helping equip and operate battlefield radiography for wounded soldiers
• Became the first woman to win a Nobel Prize, the first person (of any gender) to win Nobel Prizes in two different scientific fields, and remains the only person to win Nobel Prizes in two different sciences (Physics and Chemistry)

Named concepts

Concept	Statement	Codex page
Curie (unit, historical)	Historical unit of radioactivity, 1 Ci = 3.7×10¹⁰ decays/second	View entry
Radioactivity (term)	Spontaneous nuclear emission of radiation	View entry

Career

Born Maria Skłodowska in Warsaw, then part of the Russian Empire, Curie moved to Paris in 1891 to study at the Sorbonne, where formal higher education was far more accessible to women than in Russian-controlled Poland at the time. She met and married physicist Pierre Curie in 1895, and the couple began a close scientific partnership investigating the mysterious rays recently discovered by Henri Becquerel emanating from uranium compounds.

Working initially in a converted shed with primitive equipment, Marie and Pierre Curie processed several tonnes of pitchblende ore by hand over years of gruelling physical labour to isolate minute quantities of two new radioactive elements, polonium (1898) and radium (1898, isolated in pure form by 1902). Marie continued this research alone after Pierre's sudden death in a street accident in 1906, and she took over his professorship at the Sorbonne, becoming the university's first female professor.

Key publications

• Curie, M. (1903). Recherches sur les substances radioactives — Curie's doctoral thesis, one of the foundational documents of radioactivity research

Nobel Prizes

Marie Curie shared the 1903 Nobel Prize in Physics with Pierre Curie and Henri Becquerel "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena." She won the 1911 Nobel Prize in Chemistry alone, "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium."

Historical context

Curie's extensive, unprotected exposure to radioactive materials over decades of research — handled at a time before the health risks of radiation were understood or any safety precautions were standard practice — is now understood to have caused the aplastic anaemia that ultimately caused her death in 1934. Many of her personal papers and laboratory notebooks remain measurably radioactive today and are stored in lead-lined boxes at the Bibliothèque Nationale de France, requiring protective equipment for researchers who wish to consult them.