Glenn T. Seaborg


Searching For the Elements

In 1940, a physicist named Ed McMillan made the first transuranic element using the University of California-Berkeley's cyclotron. This was element 93, Neptunium. Transuranic means that it is an element above Uranium, and it is not naturally found in nature. After he made this discovery, scientists would no longer be looking for new elements, but making them. Once McMillan had found element 93, he set out to make 94. However, he was recruited to work on radar because of the threat of WWII reaching the United States. Glenn T. Seaborg, a coworker of McMillan's, took over where McMillan had left off, element 94.

Element 94

Neptunium was made with the Berkeley cyclotron. The cyclotron bombarded Uranium atoms with neutrons. But instead of splitting the atom, the neutron turned into a proton and element 93, Neptunium was made. Seaborg wanted to try the same thing to make element 94. He made the Neptunium, and then bombarded the atoms with neutrons. Sure enough the neutrons turned into protons. Seaborg and one of his students had to check to make sure they hadn't accidentally found an element that was already discovered. In February of 1941, they had exhausted all the known elements. They concluded that they had made element 94, Plutonium. Normally, a scientist would announced a big discovery like this, but they had to keep it a secret due to WWII.

Atomic Bomb

While Seaborg was working on making Plutonium, the Germans were working on building an atomic bomb. They had already successfully split the Uranium atom. Einstein wrote to the United States telling them that they need to work on an atomic bomb; most likely using Uranium. The problem with Uranium is that only 1% of the Uranium in the world is fissionable; this is Uranium 235. When Seaborg made Plutonium, he had to keep it a secret because if it was fissionable, then it would be a more efficient and available material to make an atomic bomb than Uranium 235. In March of 1941, again using the cyclotron, Seaborg found that Plutonium was fissionable.

Manhattan Project

After Seaborg found that Plutonium was fissionable, he went to the University of Chicago to work on the Manhattan Project. He would work on trying to find better ways to make Plutonium. Enrico Fermi built a nuclear reactor under the school's football stand to turn Uranium 238, a not fissionable kind of Uranium, into Plutonium. They found while using the nuclear reactor that an atomic bomb using Plutonium was possible. The Manhattan Project eventually made a gigantic plant in Washington to make large amounts of Plutonium. It was highly radioactive and dangerous. After a while, they were ready to test the first atomic bomb; it was made of Plutonium and was very successful. On August 6 1945, the US dropped an atomic bomb made of Uranium 235 on Hiroshima, Japan. Three days later they also dropped an atomic bomb made of Plutonium on Nagasaki, Japan. After the Manhattan Project, Seaborg could announce his discovery of Plutonium. He went on to make nine more elements. He and McMillan won the Nobel Prize in Chemistry for their work on Plutonium.
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Works Cited

Atomic Explosion Over Nagasaki Japan. Digital image. AJ Software & Multimedia, n.d. Web. 11 Apr. 2016. < nagasaki/page4.shtml>.

Einstein's Letter to President Roosevelt. Digital image. JF Ptak Science Books. John F. Ptak, n.d. Web. 11 Apr. 2016. < /letters-of-warning-einstein-and-szilard-on-the-atomic-bomb-1939-1945.html>.

Glenn Seaborg and Ed McMillan. Digital image. Berkeley Lab- 75 Years of World-Class Science. N.p., n.d. Web. 11 Apr. 2016. < milestones.html>.

Mystery of Matter: Search for the Elements. Wisconsin Public Television. PBS, 19 Aug. 15. Web. 11 Apr. 2016. <>.