阿摩線上測驗
23. A rock contains 0.688 mg of 206 Pb for every 1.000 mg of 238U present. Assuming that no lead was originally present, which all the 206Pb formed over the years has remained in the rock, and that the number of nuclides in intermediate stages of decay between 238U and 206Pb is negligible, the age of the rock is calculated to be _____ years. (For 238U, t1/2 = 4.5 ×109 years.)
(A) 3.8 × 106
(B) 3.8 × 107
(C) 3.8 × 108
(D) 3.8 × 109
(E) 3.8 × 1010
答案：登入後查看
統計： A(0), B(1), C(2), D(4), E(0) #3085487
統計： A(0), B(1), C(2), D(4), E(0) #3085487
