In a nature decay chain series starts with ""_(90)Th^(232) and finally terminates at ""_(82)Pb^(208). A thorium ore sample was found to contain 8 xx 10^(–5 ) ml of helium at 1 atm & 273 K and 5 xx 10^(–7) gm of Th^(232). Find the age of ore sample assuming that source of He to be only due to decay of Th^(232). Also assume complete retention of helium within the ore. (Half-life of Th^(232) = 1.39 xx 10^(10) Y)

In a nature decay chain series starts with ""_(90)Th^(232) and finally

1.	In a nature decay chain series starts with ""_(90)Th^(232) and finally terminates at ""_(82)Pb^(208). A thorium ore sample was found to contain 8 xx 10^(–5 ) ml of helium at 1 atm & 273 K and 5 xx 10^(–7) gm of Th^(232). Find the age of ore sample assuming that source of He to be only due to decay of Th^(232). Also assume complete retention of helium within the ore. (Half-life of Th^(232) = 1.39 xx 10^(10) Y)
Answer» ANSWER :`t = 4.89 XX 10^(9)` YEARS