Uranium-235
Uranium-235 is a radioactive isotope of uranium. Uranium-235 has 143 neutrons, 92 protons, and an isotope mass of 235.0439299. Uranium-235 has 235Pa, 235Np, and 239Pu as its parent isotopes. As it decays, it produces 231Th. Uranium-235 has a half-life of 703.8 million years. Uranium-235 makes up about 0.72% of natural uranium. When it is separated from the other uranium isotopes, it is called enriched uranium. The main use for enriched uranium is in Nuclear reactors.
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Enriched uranium is best known for its use in the bombing of Hiroshima on August 6, 1945. The bomb called Little Boy used Uranium-235. Uranium-235 can be used for nuclear fission. This fission is about 504.81 barns for slow thermal neutrons and 1 barn for fast thermal neutrons. Uranium-235 was discovered in 1935 by Arthur Jeffrey Dempster.
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