The answer is B. beta emission. Alpha emission is a particle with 2 protons and 2 neutrons. Positron emission is represented by 0 over positive 1 e. Gamma rays is 0 over 0 γ.
Jasmine have 20 fish because4 times 5 equals 20
Answer: A. uranium salt
Becquerel made a conclusion that it was the uranium that causes the images found in the photographic plates. Though his theory was disproved during the first time,he continued to develop it. Then, it is through this experiment that Becquerel discovered radioactivity.