selected
French physicist Henri Becquerel discovered the principle of radioactive decay when he exposed photographic plates to uranium salts.
Related Wikipedia articles
Henri Becquerel
French nuclear physicist (1852–1908)
Antoine Henri Becquerel was a French nuclear physicist who shared the 1903 Nobel Prize in Physics with Marie and Pierre Curie for his discovery of radioactivity.Source: Wikipedia (CC BY-SA)
Radioactive decay
Emissions from unstable atomic nuclei
Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay. The weak force is the mechanism that is…Source: Wikipedia (CC BY-SA)
Photographic plate
Target medium in photography
Photographic plates preceded film as the primary medium for capturing images in photography. These plates, made of metal or glass and coated with a light-sensitive emulsion, were integral to early photographic processes such as heliography, daguerreotypes, and photogravure.…Source: Wikipedia (CC BY-SA)
Uranium
Chemical element with atomic number 92 (U)
Uranium is a chemical element; it has symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays, usually by emitting an…Source: Wikipedia (CC BY-SA)