Marie+Curie+A3



THEORY: Marie Curie coined the term radioactivity and believed it was an atomic property of matter. Curie realized it is not the arrangement of the atoms that make something radioactive, it is the compsition and makeup of the inside of the atom. She theorized that it was how much of the radioactive material there was present that affected the radioactivity.

NEW DISCOVERY AND UNDERSTANDING ADDED TO PAST MODELS: She discovered the elements Polonium and Radium, and deemed Thorium and Uranium as radioactive. She also engineered techniques to isolate radioactive isotopes, disproving John Dalton's theory that atoms cannot be broken down. For FUTURE models of the atom, the discovery of radium helped Ernest Rutherford develop his model on the structure of the atom. She expanded on Henry's Becquerel discovery of radioactivity.