Chapter 18, Problem 30E

(a)

Interpretation Introduction

Interpretation: Number of decay events per second in $1$ curie of radiation is given. Mass of ${\text{Na}}_{\text{2}}{}^{\text{38}}{\text{SO}}_{\text{4}}$ that has an activity of $\text{10}\text{.0mCi}$ is to be determined.

Concept introduction: A process through which a unstable nuclide loses its energy due to excess of protons or neutrons is known as radioactive decay. The cause of instability of a nuclide is its inefficiency in holding the nucleus together. The curie is commonly used to measure nuclear radioactivity.

To determine: The mass of ${\text{Na}}_{\text{2}}{}^{\text{38}}{\text{SO}}_{\text{4}}$ that has an activity of $\text{10}\text{.0}\text{mCi}$.

(b)

Interpretation Introduction

Interpretation: Time taken for $99.99\%$ of a sample of sulfur- $38$ to decay is to be calculated.

Concept introduction: A process through which a unstable nuclide loses its energy due to excess of protons or neutrons is known as radioactive decay. The cause of instability of a nuclide is its inefficiency in holding the nucleus together. The curie is commonly used to measure nuclear radioactivity.

To determine: The time taken by $99.99\%$ sulfur- $38$ to decay.