Chapter 20, Problem 87AP

Interpretation Introduction

Interpretation:

The molar mass of the given isotope for the radioactive decay is to be calculated.

Concept introduction:

The rate of decay for a particular isotope is given by the rate law:

$\text{Rate = }k\text{N}$

Here, $k$ is the rate constant for the radioactive decay and $\text{N}$ is the number of atoms in the sample.

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

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

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

The number of moles of any substance is given as

$\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$