Marie Curie

Curie is the only person to win Nobel Prizes in two different sciences—Physics in 1903 and Chemistry in 1911—for her discoveries of polonium and radium and her pioneering research into radioactivity, a term she coined. Her work fundamentally changed atomic understanding, outperforming #2 Einstein in practical medical applications. She defined a new unit, the curie (Ci), equal to 3.7×10¹⁰ radioactive decays per second. Specific data: her mobile X-ray units served over 1 million soldiers during World War I. Curie remains a towering figure, with her radium research leading to a 30% reduction in cancer death rates in some early treatments. She broke gender barriers at every institution she entered, including becoming the first female professor at the University of Paris.