On analysis a sample of `.^(238)U` ore was found to contain 20.6g of `._(82)^(206)Pb` ad 23.8g of `._(92)^(238)U`. The half life period `.^(238)U` is `4.50 xx 10^(9)` years. If all the lead were assumed to have come from decay of `._(92)^(238)U`, what is the age of the ore?

On analysis a sample of uranium are was found to contain 227g of ._(82)Pb^(208) and 1.667 g of ._(92)U^(238) . The half life peiod of U^(238) is 4.51 xx 10^(9) yrs. If all the lead was assumed to have come from decay of ._(92)U^(238) , what is the age of the earth?

(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.

The half - life of ._(92)U^(238) against alpha - decay is 4.5 xx 10^(9) years. How many disintegrations per second occur in 1 g of ._(92)U^(238) ?