During nuclear explosion, one of the products is ""^(90)Sr with half-life of 28.1 years. If 1 mugof ""^(90)Srwas 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?

During nuclear explosion, one of the products is ""^(90)Sr with half-l

1.	During nuclear explosion, one of the products is ""^(90)Sr with half-life of 28.1 years. If 1 mugof ""^(90)Srwas 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?
Answer» SOLUTION :Radioactive decay follow first order kinetics, Decay constant of `""^(90)Sr(k)=(0.693)/(t_(1//2))=(0.693)/(28.1" years")=2.466xx10^(-2)"years"^(-1)` Amount LEFT after 10 years. `a=1 mug, t=10" years", k=2.446 xx 10^(-2)"years"^(-1)` Substituting the values in the first order equation `k=(2.303)/(t)"log"(a)/(a-x) or 2.466 xx 10^(-2)=(2.303)/(10)"log"(1)/((a-x))` or `log(a-x)= -0.1071` or `(a-x)="Antilog " bar1.8929=0.7814 mu G`. Amount left after 60 years `2.466 xx 10^(-2)=(2.303)/(60)"log"(1)/(a-x) or log(a-x)= -0.6425` or `(a-x)="Antilog "bar1.3575=0.2278 mu g`.