Word: curium
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Dates: during 1950-1959
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...speed. Last week a group of University of California scientists led by Professor Glenn Seaborg told how they created Element 98, which stands six steps up the periodic table (of chemical elements) from uranium, the heaviest natural element. They did it by shooting alpha particles (helium nuclei) at curium, another synthetic element, No. 96, created by a Seaborg group...
...Californians knew that the alpha particles would have to move at just the right speed. If they moved too slowly, they would bounce off the curium nuclei. If they moved too fast, they would smash the more fragile nuclei. So the scientists adjusted their old reliable 60-inch cyclotron until it emitted alpha particles with 35 million electron volts of energy. This is not high power by modern standards (see above), but it did the trick. The alpha particles entered the curium nuclei and some of them stayed there, turning the curium into Element...
...scientists named their creation "californium" after their state and university. They did not manufacture much of it. The curium they used was an invisible film weighing a few millionths of a gram, and only a small fraction of it changed into californium. The new element proved so radioactive that half of it disintegrated in 45 minutes. It took fast action to identify it and measure some of its properties before it vanished...
Atomic experts bombarded uranium with atomic particles from the cyclotron and produced neptunium, a new "synthetic" element with 93 electrons. Next, Dr. Glenn T. Seaborg and co-workers discovered plutonium (No. 94), and, four years later, at the University of Chicago, americium (No. 95) and curium (No. 96). Last week tall, gaunt, 37-year-old Chemist Seaborg and his associates were in the news again. By bombarding americium with alpha particles, they had produced another new element, with 97 electrons...