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During the nuclear explosion, one of the products is 90 Sr with half life of 6 .93 years. If 1 μ g of 90 Sr was absorbed in the bones of a newly born baby in place of Ca , how much time (in years) is required to reduce it by 90%, if it is not lost metabolically? Report your answer by rounding it up to a nearest whole number.

Correct answer

23

Step-by-step solution

t 90 % t 50 % = ln ⁡ 100 10 ln ⁡ 2 t 90 % = ln 10 ⁡ ln 2 ⁡ × t 50 % = 6.93 × ln ⁡ 10 0.693 = 23.03 years

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