Question:

Uranium-238 has a half-life of about 4.47 billion years. How long will it take for there to be only 1/8 of the original uranium-238 present in a sample? (Remember the formula is A(t)=A0(1/2)t/h,\' tabindex="0">A(t)=A_o(1/2)^t/h, where t is time in years, h is the half-life, and A0\' tabindex="0">A_o is the original amount of the radioactive substance present in the sample. In our case, we don\'t really need to know how much is originally there.)