During nuclear explosion, one of the products is `overset 90"Sr` with half-life of 28.1 years. If `1mug` of `overset90"Sr` was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 years and 60 years if it is not lost metabolically.

Strontium-90 is a radioactive isotope having a half-life of 28 years.Calculate the decay constant lambda(in s^(-1)) of Strontium-90,

The half-life of "_38^90Sr is 28 years. What is the disintegration rate of 15 mg of this isotope.

Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as -(dN)/(dt)=lambdaN Where lambda= decay constant, N= number of nuclei at time t, N_(0) =initial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) Half-life period of U is 2.5xx10^(5) years. In how much time will the amount of U^(237) remaining be only 25% of the original amount ? a) 2.5xx10^(5) year b) 1.25xx10^(5) years c) 5xx10^(5) years d) none of these

Strontium-90 decays with the emission of a beta- particle to form Ytrium-90 .The reaction is represented by the equation _(38)Sr^(90) rarr _(39)Y^(90) + _(-1)e^0 + 0.55 MeV the decay constant is 0.025 year ^(-1) . At the time of purchase of a Stronituim-90 source the activity is 3.7 xx 10^6 Bq . Calculate ,for this sample of strontium,the initial number of atoms.