In nature a decay chain series starts with ""_90^232Th and finally terminates at ""_82^208Pb. A thorium ore sample was found to contain 8 xx 10^(-5) mL of helium at STP and 5xx10^9-7)g of ""^232Th . Find the age of the ore sample assuming the source of helium to be only the decay of ""^232Th . Also, assume complete retention of helium within the ore. Half-life of""^232Th= 1.39 xx 10^10years.

In nature a decay chain series starts with ""_90^232Th and finally ter

1.	In nature a decay chain series starts with ""_90^232Th and finally terminates at ""_82^208Pb. A thorium ore sample was found to contain 8 xx 10^(-5) mL of helium at STP and 5xx10^9-7)g of ""^232Th . Find the age of the ore sample assuming the source of helium to be only the decay of ""^232Th . Also, assume complete retention of helium within the ore. Half-life of""^232Th= 1.39 xx 10^10years.
Answer» SOLUTION :`""_90^232Th to ""_82^208Pb + 6""_2^4He + 4 ""_(-1)^0 e` ` 4.89 XX 10^9` years