Irene Joliot-Curie and her husband Frederic were both nuclear physicists who experimented with the manipulation of elements, particularly as it related to their radioactivity. Her crowning achievement came in 1936 with the discovery that radioactive isotopes could be created from otherwise stable elements.
The daughter of famed scientists, Pierre and Marie Curie, Irene continued her parent's work in the realm of molecular physics. Two of her most successful experiments were the creation of radioactive nitrogen by fusing boron with alpha particles and the creation of a radioactive phosphorus isotope from aluminum. Joliot-Curie also conducted extensive research on the atom that was instrumental in the discovery of the neutron. Her experiments in this area led to the discovery of uranium fission.
The creation of these radioactive elements have made a vast impact on modern life, particularly in the medical field. The ability to create artificial radioactive material has made treatment for certain diseases possible where it was not before. After this discovery, radioactive material was able to essentially be mass produced for the treatment of disease, giving medical professionals a new weapon against disease. The most prominent of these diseases is cancer, for which radiation therapy is a near universal treatment after diagnosis.