Uranium Saltss Lab Report

Henri Becquerel became the first to discover radioactivity, gamma rays, and alpha and beta particles by studying uranium and other radioactive materials. Becquerel believed that Uranium phosphoresced, or absorbed energy from the sun and then emitted it in the form of light and radiation. He tested this by leaving Uranium salts, or potassium uranyl sulfate, in the sun for several hours and then leaving it, along with a coin, on a photographic plate. A photographic plate was used as an early photograph taking device. It was paper thin and darkened when it came into contact with light. When Becquerel left the plate with the Uranium salts on it he saw that ,once the plate was processed, it was blackened where the Uranium salts were placed. When Becquerel did this experiment again, it was a cloudy day, and the Uranium salts received little sunlight.
To his surprise, the plates had the same amount of darkness as the previous plates. This led Becquerel to believe that the uranium salts did, in fact, not phosphoresce. After another experiment, where he placed uranium salts on three different photographic plates, one with nothing in between the uranium and the plate, now with glass in between, and one with a sheet of tin between the plate and the salts, in a dark room. When he saw that the plates were darkened even though they were not exposed to light, he concluded that they released invisible radiation. At the time, he believed that these rays were x-rays, but his later experiment proved