sasikarnsingudom sasikarnsingudom 26-04-2024 Chemistry Answered The contents of a rock have a 206Pb to 238U mass ratio of 0.175:1.00. Assuming that the rock did not contain any 206Pb at the time of its formation, determine the age of the rock. Uranium-238 decays to lead-206 with a half-life of 4.5 billion years.