Chapter 12, Problem 12.121CHP

(a)

Interpretation Introduction

Interpretation:

The fraction of strontium-90 remains after three half-life periods has to be calculated.

Concept Introduction:

Half-life period:

It is the time required for the reactant (substrate) concentration reduces to one-half of its initial concentration.

$\begin{array}{l}{\text{t}}_{\text{1/2}}\text{=}\frac{\text{0}\text{.693}}{\text{k}}\\ \text{where,}\\ {\text{t}}_{\text{1/2}}\text{-}\text{half-life}\text{period}\\ \text{k}\text{-}\text{rate}\text{constant}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The value of decay constant for strontium-90 has to be calculated.

Concept Introduction:

Half-life period:

It is the time required for the reactant (substrate) concentration reduces to one-half of its initial concentration.

$\begin{array}{l}{\text{t}}_{\text{1/2}}\text{=}\frac{\text{0}\text{.693}}{\text{k}}\\ \text{where,}\\ {\text{t}}_{\text{1/2}}\text{-}\text{half-life}\text{period}\\ \text{k}\text{-}\text{rate}\text{constant}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The number of years required for $\text{99}\text{\%}$ of strontium-90 disappear has to be calculated.

Concept Introduction:

Half-life period:

It is the time required for the reactant (substrate) concentration reduces to one-half of its initial concentration.

$\begin{array}{l}{\text{t}}_{\text{1/2}}\text{=}\frac{\text{0}\text{.693}}{\text{k}}\\ \text{where,}\\ {\text{t}}_{\text{1/2}}\text{-}\text{half-life}\text{period}\\ \text{k}\text{-}\text{rate}\text{constant}\end{array}$