Chapter 20, Problem 20.31QP

Interpretation Introduction

Interpretation:

The ratio between ${\text{U}}^{\text{238}}$ to ${\text{Pb}}^{\text{206}}$ in a $\text{1}{\text{.7×10}}^{\text{8}}$ years old rock should be determined.

Concept Introduction:

• Half-life period: The time required to reduce to half of its original value and it is denoted by ${\text{t}}_{\text{1/2}}.$
• This term is popularly use in nuclear chemistry, to describe the stability & instability of atoms or radioactive decay.
• For determination of first order rate constant K in half –life period we use the equation,

$\text{k=}\frac{\text{0}\text{.693}}{{\text{t}}_{\text{1/2}}}$

• The half-life in first order does not depend upon the initial concentration.