Henri Becquerel

Antoine Henri Becquerel (French: Antoine Henri Becquerel, December 15, 1852 - August 25, 1908), first translated Becquerel, was a French physicist. Together with the Curies, he won the 1903 Nobel Prize in Physics for discovering the phenomenon of natural radioactivity. The becquerel (Bq), the SI unit of radioactivity, is named after him. Inspired by Röntgen's discovery of X-rays, Bekele studied the phosphorescence of uranium and potassium bisulfates. He exposed the two materials to sunlight and then wrapped the exposed materials and photosensitive film together in black paper. After a period of time, the film is developed and the image of uranium crystals appears on the film. Beckler speculated: "The phosphorescent rays emitted by the material can pass through the opaque paper." At first he thought the crystal was absorbing the sun's energy and then emitting X-rays. On February 26 and February 27, 1896, Bekele planned to expose the wrapped uranium and photosensitive films to the sun, but Paris was cloudy and the sunlight was intermittent, which did not achieve the ideal experimental results, so he returned the materials to the drawer and stored them in the dark. It was cloudy for the next few days, and the sunlight stimulation experiment could not be carried out. When he developed the film on March 1, he expected that the intensity of phosphorescence would be very weak because the sunlight did not excite it for long, and he could only see a blurry image. Unexpectedly, he saw a very clear image, which surprised him. Further experiments showed that uranium can emit radiation without the need for an external energy source such as sunlight, so he discovered radioactivity, the spontaneous emission of radiation from the material. In 1900, Becqueler, who was measuring the properties of beta particles later in his life, realized that they had the same measurements as high-speed electrons leaving the nucleus of an atom. In 1901 Bekele discovered that radiation could be used in medicine. He discovered this phenomenon when he placed a piece of radium in his vest pocket and realized that he had been burned by it. This discovery led to the development of radiotherapy, which is now used to treat cancer. Bekele did not live long after discovering radioactivity. He died in Le Croisic, France on August 25, 1908, at the age of 55. The cause of his death is unknown, but reports say "his skin was severely burned, possibly from handling radioactive material."