German physicist R?ntgen discovered X-rays in 1895, and in 1896, French scientist Becquerel discovered the spontaneous emission of uranium-containing materials. The Curies were determined to explore the secrets of this. They chose uranium rays as a scientific research project to discover new, highly radioactive elements contained in uranium pitch mines. They first discovered a new radioactive element, which Marie Curie named polonium in memory of her motherland, Poland; then they discovered the more radioactive radium and determined to refine it. Since they could not afford uranium ore containing radium, they had to use cheap uranium pitch residue and borrow a weatherproof shed as a laboratory. Braving the scorching heat and cold, using extremely simple tools, and enduring the pungent smell, after 54 months of hard work, 0.12 grams of radium chloride was finally extracted from dozens of tons of uranium pitch residue, and the atomic weight of radium was accurately determined. At 225, it is about 2 million times more radioactive than uranium. In 1903, Marie Curie received her doctorate. In the same year, the Curies were awarded the Nobel Prize in Physics for their outstanding contributions to the study of radiation phenomena. After the discovery of radioactive elements, especially radium, radiology and particle physics were born.