Marie and Pierre Curie were a husband and wife team of scientists who made groundbreaking discoveries in the field of radioactivity. Marie Curie was the first woman to win a Nobel Prize and the only person to win two Nobel Prizes in two different sciences. She was also the first female professor at the University of Paris. Pierre Curie was a physicist and chemist who worked with his wife on their research. Together, they discovered the elements polonium and radium, which led to the development of X-rays and other medical treatments. They also developed the theory of radioactivity, which revolutionized the understanding of atomic structure.