Chapter 19, Problem 19.8A

Interpretation Introduction

Interpretation:

Determine the half-life.

Concept introduction: Half-life of radioactive substance is:

$t_{\frac{1}{2}}=\frac{0.693}{k}$ .

The integrated rate law for radioactive decay is $\ln \left(\frac{N_t}{N_0}\right)=-kt$

To determine: The half-like if cesium $-137$ is a radioactive isotope released as a result of the nuclear Fukushima diarchy disaster in Japan in $2011\text{ if }89.2\%$ remains after $5$ years.