Marie Curie

Nobel 1903 in physics (shared with Pierre Curie and Henri Becquerel) “in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel” — she coined the term “radioactivity”, showed it is an atomic property, and detected polonium and radium in pitchblende. Nobel 1911 in chemistry “in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element” — through laborious fractional crystallisation of tonnes of ore she obtained pure $\ce{RaCl2}$ and determined radium’s atomic weight.