mmols U at finish = 270
mmols Pb at finish = 110
mmol U at start = 380
ln(380/270) = kt
Solve for t
You need k and k = 0.693/t1/2 = ?
A rock contains 270 mmol of 238 U (t1/2= 4.5*10^9 yr) and
110 mmol of 206 Pb. Assuming that all the 206 Pb comes from decay
of the 238 U, estimate the rock’s age.
1 answer
1 answer