Chapter 20, Problem 99AP

Interpretation Introduction

Interpretation:

The most abundant radioactive isotopes in the earth’s crust are to be identified; and the reason as to why they are still present, is to be explained.

Concept introduction:

Nearly all radioactive decay is of the first order and its rate constant is given as follows:

$k\text{ = }\frac{0.693}{t_{1/2}}$

Here, $t_{1/2}$ is the half-life of the radioactive substance.

The half-life $\left(t_{1/2}\right)$ of a radioactive substance decides the rate constant, that is the rate of disintegration per unit time. Higher the value of $t_{1/2}$, lower will be the rate constant.