Chapter 25.4, Problem 1RC

Interpretation Introduction

INTERPRETATION:

The percentage of thorium decomposed after the given period of time should be determined using the concepts of half life.

CONCEPT INTRODUCTION:

Radioactive decay:

A nucleus undergoes disintegration in-order to become stable by emitting radiations such as alpha, beta and gamma particles.

Radioactive series:

The series in which successive disintegration of unstable nuclei is formed until a stable nucleus is formed.

Half life:

The time used for the decay of the half of the radioactive isotope to undergo decay.

$\text{Half}\text{life}\text{,}{\text{t}}_{\frac{\text{1}}{\text{2}}}\text{=}\frac{\text{0}\text{.693}}{\text{λ}}\text{where}\text{λ}\text{is}\text{the}\text{decay}\text{constant}$

${\left(\frac{\text{1}}{\text{2}}\right)}^{\text{number}\text{of}\text{half}\text{lives}}\text{=}\text{decimal}\text{amount}\text{remaining}$

Equation for number of half lives passed:

$\text{No}\text{.}\text{of}\text{half}\text{lives}\text{=}\frac{\text{Total}\text{time}}{\text{Half}\text{life}}$