The Curries successfully isolate radioactive radium salts from pitchblende

 

On April 20, 1902, Marie and Pierre Curie successfully isolated radioactive radium salts from pitchblende, a mineral, in a laboratory in Paris, France. Inspired by French physicist Henri Becquerel’s 1896 experiment on phosphorescence, or the phenomenon that allows certain objects to glow in the dark, the Curries were able to find traces of two radioactive elements—polonium (Element 84) and radium (Element 88).