Chapter 16, Problem 85CP

Interpretation Introduction

Interpretation:

The initial activity, in microcuries, of the sample needs to be determined.

Concept introduction:

• The half-life of a radioisotope is the time that is needed to disintegrate half of the atoms present in a sample.
• The decay equation is,

${\text{A=A}}_{\text{0}}{\text{e}}^{\text{-λt}}$

Where A is the activity in the time (t), A₀ is the initial activity, $\text{λ}$ is the decay constant and t is the time.

• The decay constant is equal to,

  $\text{λ = }\frac{\text{ln}\text{2}}{{\text{t}}_{\frac{\text{1}}{\text{2}}}}$

where $\text{λ}$ is the decay constant and ${\text{t}}_{\frac{\text{1}}{\text{2}}}$ is the half-life.