18 ALPHA
6 BETA
AGE=7.12*10TO THE POWER OF 8
^{238}_{92}U is radioactive and it emits alpha and beta particles to form ^{206}_{82}Pb.
Calculate the number of alpha and beta particles emitted in this conversio. An ore of ^{238}_{92}U is found to contain ^{206}_{82}Pb and ^{238}_{92}U in the wieght ratio 0.1:1.
The half life period of ^{238}_{92}U is 4.5x109 years.
Find the age of the ore.
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15 Answers
1see N=Noe-λt gives the no of remianing U atoms so the no of U atoms converted to Pb is No-N
given ratio No-N / N
then solve.
1using formula for t1/2 find rate constant and substitute values as given by srinath bhaiya
1U238/Pb206= 3/1
N/N-N0=3/1
N/N0=3/4
but as N=N0 e-\lambdat=4/3
\lambdat= log 3(4/3)
tlog e2/T= log e(4/3) as \lambda=loge2/T
t=1.86x109 years