Marie and Pierre Curie proved the existence of the new element radium when they chemically isolated one-tenth of a gram of pure radium chloride.
Marie and Pierre Curie were both pioneering scientists in their own right, but as a research partnership they are most famous for their work on radioactivity. Inspired by the work of the French physicist Henri Becquerel who had been the first person to discover radioactivity, the Curies’ work won them the 1903 Nobel Prize in Physics which they shared with Becquerel himself.
Marie had been born and raised in Poland but, since women were not permitted to attend university there, she moved to France to take up a place to study at the Sorbonne in Paris. Having secured degrees in both physical sciences and mathematics by 1894 she married Pierre, an established physicist, whom she had met through a mutual friend. Marie subsequently began to pursue a Ph.D. for which she studied the recently-discovered rays emitted by uranium.
Having coined the term radioactivity to describe the radiation she observed, Curie focused on the minerals pitchblende and torbernite in her search for materials that emitted more radiation than uranium itself. Inspired by his wife’s discovery that the element thorium was radioactive, Pierre dropped his own research in 1898 to work with her. In July they published a joint paper announcing the existence of an element they named polonium, and in December they did the same for radium.
To unequivocally prove their existence, the Curies sought to isolate them from pitchblende. Having processed tons of the mineral, they eventually obtained one-tenth of a gram of radium chloride on 20 April 1902, for which they shared the 1903 Nobel Prize in Physics.