Marie Curie, the Premier Chemist, Co-Discoverer of Radiation and Radioactivity

Intrigued by Henri Becquerel’s discovery that uranium compounds emitted “rays” that could penetrate opaque objects and fog photographic plates, Marie Curie began her scientific quest that resulted in the discovery of radioactivity. By systematically studying uranium compounds and later thorium, she found that the intensity of the emitted “Becquerel rays” was proportional to the amount of U or Th present in the sample, and concluded that emission of “rays” was an atomic property of the element regardless of its chemical or physical state. Focusing on pitchblende, a uranium oxide ore, Marie found that it was 4-5 times more radioactive than could be explained by the amount of U present. This led her to postulate the existence of a new element and started her down the arduous path of chemically separating what ended up being tons of uranium-bearing material. Her efforts were rewarded with the discovery of not one, but two new elements, a Bi-like element (polonium) and a Ba-like element (radium). Madame Curie demonstrated, for the first time in history an alchemist’s dream, that an element could be transmuted into another element. This discovery revolutionized chemistry and clearly secured her place in history as both a woman and a scientist. This talk will recount the many discoveries and amazing scientific career of Madame Curie.