History of discoveries in the field of radioactivity

History of discoveries in the field of radioactivity
200px|náhled|vpravo|Pierre a Marie Curie v ich parížskom laboratóriu v roku 1907.

In 1896 French scientist Henri Becquerel discovered rádioaktivitu. Becquerel was interested in fosforescenciu. He discovered that some materials glow in the dark after exposing to the light. Henri expected that the glow produced by röntgenovými lúčmi in the monitor could be associated with phosphorescence. He wrapped the photographic plate in black paper and placed various phosphorescent salts on it. All the results were negative until he used the uranium salt. The result of this mixture caused the board to blacken even though the board was wrapped in black paper. These radiations, (uránové lúče) were therefore named "Becquerel Rays".

Soon it was clear that the blackening of the plate had nothing to do with phosphorescence, as it was clear that it was a form of invisible radiation that could pass through the paper and cause a reaction and subsequent blackening if the plate was exposed to light.

At first, it appeared that the newly discovered type of radiation was similar to the previously discovered X-rays. Other research involving Henri Becquerel, Ernest Rutherford, Paul Villard, Pierre Curie, Marie Curie and others showed that this form of radioactivity was considerably more complex. Rutherford was the first one who realized that all decomposition follows a mathematical exponential formula. He and his student Frederick Soddy were the first who also realized that many decomposition processes resulted in the transmutation of one element into another. Subsequently, the Fajans-Soddy law of radioactive displacement was formulated to describe the products of alfa and beta decomposition.

Soon scientists discovered that many other chemical elements, besides uranium, have radioactive isotopes. The systematic search of total radioactivity in uranium ores was also directed by Pierre and Marie Curie when they isolated two new elements: polonium and radium. Apart from the radioactivity of radium, the chemical similarity of radium to barium makes the two elements difficult to differentiate.

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Radioaktivita

Source
http://world-nuclear.org/information-library/current-and-future-generation/outline-history-of-nuclear-energy.aspx