There appears to be a distinct lack of agreement in the physics community on what exactly Marie Curie did for atomic theory.
Many journals state that Curie was responsible for shifting scientific opinion from the idea that the atom was solid and indivisible to an understanding of subatomic particles. However, JJ Thompson had already discovered the electron prior to Curie's work, and Rutherford proved the nature of atomic structure – so what did Marie Curie really do for atomic theory?
Best Answer
From: NobelPrize.org
"Her continued systematic studies of the various chemical compounds gave the surprising result that the strength of the radiation did not depend on the compound that was being studied. It depended only on the amount of uranium or thorium. Chemical compounds of the same element generally have very different chemical and physical properties: one uranium compound is a dark powder, another is a transparent yellow crystal, but what was decisive for the radiation they gave off was only the amount of uranium they contained. Marie drew the conclusion that the ability to radiate did not depend on the arrangement of the atoms in a molecule, it must be linked to the interior of the atom itself.
This discovery was absolutely revolutionary. From a conceptual point of view it is her most important contribution to the development of physics. "