Whose work isolated radium and polonium from pitchblende?

Marie and Pierre Curie built on Becquerel’s discovery by investigating pitchblende, a uranium-rich ore that was more radioactive than expected. In 1898, they reported two new radioactive elements: polonium and radium. Their work required processing enormous quantities of ore and painstaking chemical separation. The Curies’ discoveries transformed chemistry and physics, and Marie Curie became the first person to win two Nobel Prizes. Their research helped establish radioactivity as a major scientific field.