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.