A certain substance has a half-life of 5.0 hours. How many nuclei of the substance are required to give an initial activity of 6.0 μCi? 1 Ci = 3.7 × 10¹⁰ Bq. A) 5.8 × 10⁹ nuclei B) 8.5 × 10⁸ nuclei C) 6.3 × 10⁸ nuclei D) 3.2 × 10⁹ nuclei E) 2.4 × 10⁹ nuclei

Question

Quizplus · Accepted Answer

The initial activity (A) is related to the number of nuclei (N) by A = λN, where λ is the decay constant. λ can be calculated using the half-life (T₁/₂) with λ = ln(2)/T₁/₂. Convert the activity from μCi to Bq and solve for N.

A Certain Substance Has a Half-Life of 5