One of the hazards of nuclear explosions is the generation of 90sr andits subsequent incorporation in place of calcium in bones. this nuclide emitsβrays of energy 0.55 mev, and has a half-life of 28.1 y. suppose 1.00 μg wasabsorbed by a newly born child. how much will remain after (a) 18 y, (b) 70 yif none is lost metabolically?

Explanation:

Initial mass of the isotope 90-Sr in baby= 1.00 μg

Formula used :

where,

= initial mass of isotope

N = mass of the parent isotope left after the time, (t)

= half life of the isotope  = 28.1 years

= rate constant

a) Time taken by the sample, t = 18 years

0.6415 μg  will remain after 18 years.

b) Time taken by the sample, t = 70 years

0.1779 μg  will remain after 70 years.