⁹⁰Sr is an isotope produced from atmospheric testing of nuclear bombs. If nuclear testing was stopped in 1960, what percentage of radioactivity due to ⁹⁰Sr remained in 2000? The half-life of ⁹⁰Sr is 28.5 years.

Question

Quizplus · Accepted Answer

The time between 1960 and 2000 is 40 years. Using the formula N = N₀(1/2)^(t/T), where N is the remaining fraction of radioactivity, N₀ is the initial fraction (which we'll assume is 1), t is the time elapsed, and T is the half-life, we can calculate: N = (1/2)^(40/28.5) ≈ 0.378 So, approximately 37.8% of the radioactivity due to ⁹⁰Sr remained in 2000. Therefore, the best choice is B.

90Sr Is an Isotope Produced from Atmospheric Testing of Nuclear

⁹⁰Sr Is an Isotope Produced from Atmospheric Testing of Nuclear