Which two elements did Curie discover?

• A. Uranium and Thorium
• B. Polonium and Radium
• C. Polonium and Uranium
• D. Radon and Polonium

Answer: (B)

Curie’s crucial finding was that pitchblende contained not just uranium but two additional radioactive elements, identifiable by a different level and type of radioactivity. By isolating and analyzing the radioactive components, she and her husband demonstrated the existence of two new elements: polonium, named after Poland, and radium, notable for its intense, persistent radioactivity. These discoveries expanded the known elements and showed that radioactivity isn’t limited to elements already on the periodic table. Uranium and thorium were already known, and radon was discovered by other scientists, so polonium and radium are the two credited to Curie.