The phenomenon of radioactivity was first discovered by
Answer Details
The phenomenon of radioactivity was first discovered by Henn Becquerel. In 1896, Becquerel discovered that a uranium compound placed near a photographic plate caused the plate to darken. This phenomenon occurred even when the uranium compound was not exposed to light, suggesting that it was emitting a type of radiation that could penetrate through solid objects. Becquerel's discovery paved the way for further research into radioactivity, which eventually led to the development of nuclear physics and its applications.