how many neutrons does the most common isotope of uranium have
Best Answer: U-238 is by far the most common isotope of Uranium found naturally, 99.284%. It has 238 nucleons, 92 of which are protons. The remaining 146 are neutrons. U-235, which accounts for 0.711% of all Uranium found naturally, is the useful one for fission reactors (and bombs), has 235 - 92 = 143 neutrons. U-234 is also found in extremely small quantities, 0.0058%, and has 142 neutrons.