The curies took pure uranium and a uranium-containing substance. when they measured the amount of radioactivity, there was more in the uranium-containing substance than the pure uranium. which idea did the curies most likely develop? a. there are more radioactive substances than uranium. b. radioactivity is magnified by mixed substances. c. the date of the material varied between the pure substance and mixed substance. d. the half-life of uranium in a mixed substance is less than pure uranium.

The answer is option "A, There are more radioactive substances than uranium".

Curie has considered the minerals containing uranium or thorium, and as per the perspectives simply expressed, these minerals are on the whole radioactive. Yet, in making the estimations, she found that sure of these were more dynamic than they ought to have been by the substance of uranium or thorium. Curie at that point made the presumption that these substances contained radioactive chemical components which were so far not known yet.