Respuesta :
There were 2 notable Curies in history, Marie and Pierre. They were actually married couple. They both discovered Polonium and Radium from pitchblende). These elements were radioactive hence the discovery of radioactivity. R Their main discovery is how they could isolate the radioactive material. She also further developed the X-ray.
Answer:
A) A material’s radioactivity cannot be changed by altering the material physically.
Explanation:
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