Marie Curie is a world renowned scientist commonly known for her contribution on the Manhattan Project (although she wasn't there), as well as her discovery of the elements: radium and pollonium. She thought of radium to be a health remedy however she did not know the amount of toxicity it had. She contributed to the atomic theory by proposing that radioactive atoms emit gamma rays as well as alpha particles and and other particles.
Before Curies death scientist had limited knowledge about the dangers of radiation. Curie's scientific expedition explored radiation and its effects. During Curie's time there was a lot of scientific investigation in elements and the atomic theory.
Curie used radiation as a tool to attempt to cure many diseases and conditions such as cancer. The tools she used was later used in the foundation of the X-Ray.
Curie left a major imprint on modern day science by exploring radiation and its affects on the body as well as investigating how radioactive atoms work.
Bibliography: https://www.atomicheritage.org/profile/marie-curie , https://stfc.ukri.org/news-events-and-publications/features/marie-curie/ , https://www.nobelprize.org/prizes/physics/1903/marie-curie/biographical/