Correct Answer: Marie Curie

Solution : The correct answer is Marie Curie 

Marie Curie first discovered the radioactive elements polonium and radium, Marie continued to investigate their properties. In 1910 she successfully produced radium as a pure metal, which proved the new element's existence beyond a doubt.

While uranium was the first radioactive element to be discovered, radium was much more popular, as it was a spontaneously luminous material that emitted an incredible quantity of radiation.

Radium (chemical symbol Ra) is a naturally occurring radioactive metal. Radium is a radionuclide formed by the decay of uranium and thorium in the environment. The most common isotopes

Final answer is Marie Curie