On the Folder tab, in the Properties group, click Folder Properties. On the Outlook Address Book tab, clear the Show this folder as an e-mail Address Book check box. If you want to turn Suggested Contacts off, do the following: Click the File tab.
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.
What does the total number of protons and neutrons in the nucleus of an atom determine? This is the mass number of the atom, indicating relative mass of an isotope. For example uranium-235 (235U) is a lighter atom than uranium-238 (238U) because while both is â¦ otopes have 92 protons (the atomic number), the first has 3 fewer neutrons.