What is Uranium-235?
[[File:Fission chain reaction.svg|thumb]] '''Uranium-235''' is a [[radioactive]] [[isotope]] of [[uranium]]. Uranium-235 has 143 neutrons, 92 protons, and an isotope [[Atomic mass unit|mass]] of 235.0439299. Uranium-235 has <sup>235</sup>Pa, <sup>235</sup>Np, and <sup>239</sup>Pu as its parent isotopes. As it decays, it produces <sup>231</sup>Th. Uranium-235 has a [[Half-life (element)|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 reactor]]<nowiki/>s. 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. [[File:Kernspaltung.svg|thumb]] {{chem-stub}} [[Category:Isotopes]] [[Category:Uranium]]