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.
Remember that isotopes have the same number of protons but different numbers of neutrons. The most common isotope of hydrogen has only one proton and zero neutrons. If both protons and neutrons have a mass of about 1 amu (atomic mass unit), the mass of this atom would be about 1 amu (just the mass of the proton). This isotope of hydrogen has a special name, protium, and it makes up over 99.98% of all the hydrogen atoms.