jan 1, 1896 - Antoine Henri Becquerel
Description:
French physicist Antoine Henri Becquerel's experiments led to the discovery of radioactivity. He observed that the element uranium can blacken a photographic plate, even though separated from it by glass or black paper. He also observed that the rays that produce the darkening are capable of discharging an electroscope, indicating that the rays possess an electric charge.Added to timeline:
Date:
jan 1, 1896
Now
~ 129 years ago