Half lives of two uranium samples U238 and U235 are known to be 4.5 *10^9 and 7.1*10^8 yr ,respectively .if the earth was formed with equal amts of the two isotopes estimate the current age of the earth given that uranium ores are 99.29% U238 and .71% of U235 by number
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4I din't get the second part of the qs "given that uranium ores are 99.29% U238 and .71%
of U235 by number "
But this is my try
N = N0 e-λ t
λ = 0.693/t1/2
Using the abv
99.29 x 10-2 = N0 e-λ1 t λ1 = 0.693 / 4.5 x 10^9
71 x 10^ - 4 = N0 e-λ2 t λ2 = 0.693 / 7.1 x 10^8
N0 is same in both cases
Solving both n finding out t we get the age of the earth
