107 Stories About Chemistry
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Nuclear chemistry knows many methods of producing these elements. At present, 12 transuranium elements are known, namely: neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, lawrencium, and kurchatovium, the latter being the heaviest transuranium element synthesized just recently (in 1964) by a group of Soviet physicists headed by P. Flerov. One of the transuranium elements, that having the atomic number 102, has not yet been named. Imagine the surprise of a mason who one day just finished laying the bricks for a new storey of a house, and on the next found that all his work had disappeared. Such is precisely the predicament of investigators studying the chemical properties of the heavy transuranium elements. These elements are very unstable, their lifetime being a matter of minutes or even seconds. When working with ordinary elements the chemist is not pressed for time. But when he lays his hand on the short-lived representatives of the Periodic Table, especially the heavy transuranium elements each minute of the investigation is "worth its weight in gold." Not only are the objects being studied likely to disappear any second, the amounts at the chemist's disposal are very scanty, sometimes literally a few atoms. This makes it necessary to employ special methods of investigation. They are governed by a new young branch of chemistry known as radiochemistry, the chemistry of the radioactive elements.
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