InterviewSolution
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InterviewSolution
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During nuclear explosion, one of the products is `.^(99)Sr` with half`-` life of `28.1 `years. If `1 mug` of `.^(90)Sr` was absorbed in the bones of a newly born baby instead of calcium, how much of its will remain after 10 years and 60 years if it is not lost metabolically. |
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Answer» `t_(1//2) = 28.1 Y: k = (0.693)/(t_(1//2))= 0.693/28.1 Y^(-1)` All radioactive explosions follow first order kinetics. `t= (2.303)/k log a/(a-x)` Ist case, a=1 mug, t= 10 Y, `k=0.693/28.1 Y^(-1)` `10Y = 2.303/(0.693//28.1 Y^(-1)) log a/(a-x)` `loga/(a-x) = (10Y)xx(0.693//28.1Y^(-1))/(2.303) = 0.107` `a/(a-x)` = Antilog 0.107 = 1.279 `(a-x) = a/1.279=(1"mug")/(1.279)=0.7819` mug IInd case, a=1mug, t=60Y, `k=0.693//28.1 Y^(-1)` 60 Y `= (2.303)/(0.693//28.1Y^(-1))= log a/(a-x)` `loga/(a-x) = (60Y) xx (0.693//28.1Y^(-1))/(2.303) = 0.642` `a/(a-x)`= Antilog 0.642 = 4.385 `(a-x) = a/4.385 = (1"mug")/(4.385) = 0.2280` mug |
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