Answer:
The weight of Strontium-90 will reduce to \(0.25\) Kg in \(58\) years.
Explanation:
Given -
Radioactive isotope sample of Strontium-90 \(= 1\)Kg
Half life of Strontium-90 \(= 29\) years
After first half life (i.e 29 years), the weight of Strontium-90
\(= \frac{1}{2}\\= 0.5\) Kg
After second half life (i.e 58 years), the weight of Strontium-90
\(= \frac{0.5}{2}\\= 0.25\) Kg
Thus, the weight of Strontium-90 will reduce to \(0.25\) Kg in \(58\) years.
