Chapter 20, Problem 20.97QP

Interpretation Introduction

Interpretation: The diagram should be identified for the closely representing the sample of X after 20 days.

Concept Introduction:

• Half-life period: The time required to reduce, half of its original value.
• This 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

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

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

Formula:

Age calculation:

$\text{ln}\frac{{\text{N}}_{\text{t}}}{{\text{N}}_{\text{0}}}\text{=-kt}$

Calculate the age and rate constant:

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

Given:

X isotope to Y isotope decay with a Half – life of 45 days

To identify: The correct suture most closely represents the sample of X after 20 days.