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प्रश्न
During nuclear explosion, one of the products is 90Sr with half-life of 28.1 years. If 1μg of 90Sr 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.
उत्तर
`t_(1/2)` 90Sr = 28.1 yr, k = `0.693/28.1 "yr"^-1`
Now, t = `2.303/"k" log "a"/(("a" - "x"))` ...(a = 1 µg)
After 10 years, 10 = `(2.303 xx 28.1)/0.693 log 1/(("a" - "x"))`
The remaining amount of Sr = (a − x) = 0.7814 µg
After 60 years, 60 = `(2.303 xx 28.1)/0.693 log 1/(("a" - "x"))`
The remaining amount of Sr = 0.2278 µg
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