The half life period of uranium is 4.5 billion years. After 9.0 billion years, the number of moles of heliumm liberated from the following nuclear reaction will be:
`._(92)^(238)U to ._(90)^(234)Th + ._(2)^(4)He`
Initially there was I mole uranium.

In the nuclear reaction ""_(92)U^(238) to ""_(z)Th^(A) + ""_(2)He^(4) , the values of A and Z are

For the following raction, which is correct? ""_92U^238rarr""_90Th^234+""_2He^4

(a) On analysis a sample of uranium ore was found to contian 0.277g of ._(82)Pb^(206) and 1.667g of ._(92)Pb^(206) and 1.667g of ._(92)U^(238) . The half life period of U^(238) is 4.51xx10^(9) year. IF all the lead were assumed to have come from decay of ._(92)U^(238) , What is the age of earth? (b) An ore of ._(92)U^(238) is found to contain ._(92)U^(238) and ._(82)Pb^(206) in the weight ratio of 1: 0.1 The half-life period of ._(92)U^(238) is 4.5xx10^(9) year. Caluculate the age of ore.

(a) On analysis a sample of uranium ore was found to contain 0.277g of ._(82)Pb^(206) and 1.667g of ._(92)U^(238) . The half life period of U^(238) is 4.51xx10^(9) year. If all the lead were assumed to have come from decay of ._(92)U^(238) , What is the age of earth? (b) An ore of ._(92)U^(238) is found to contain ._(92)U^(238) and ._(82)Pb^(206) in the weight ratio of 1: 0.1 The half-life period of ._(92)U^(238) is 4.5xx10^(9) year. Calculate the age of ore.