The half life of ._38^90Sr is 28 years. The disintegration rate of 15 mg of this isotope is of the order of

The half life of ._38^90Sr is 28 years. The disintegration rate of 15

1.	The half life of ._38^90Sr is 28 years. The disintegration rate of 15 mg of this isotope is of the order of
Answer» `10^11` Bq `10^10` Bq `10^7` Bq `10^9` Bq Solution :Here, `T_(1//2)`=28 years=`28xx3.154xx10^7` s Asnumber of ATOMS in 90 G of `._38^90Sr=6.023xx10^23` `therefore ` NUMBER of atoms in 15 mg of `._38^90Sr =(6.023xx10^23)/90xx15/1000` i.e., `N=1.0038xx10^20` Rate of DISINTEGRATION, `=0.693/T N=(0.693xx1.0038xx10^20)/(28xx3.15xx10^7)` `=7.877xx10^10 "Bq" approx 10^10` Bq

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The half life of ._38^90Sr is 28 years. The disintegration rate of 15 mg of this isotope is of the order of

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