Chapter 20, Problem 20.82SP

Interpretation Introduction

Interpretation:

Interpret the energy change Δ E (kJ/mol) when a-particle is emitted from $\text{I}\text{r}$ to produce $\text{R}\text{e}$ as shown below:

$\text{I}\text{r}\stackrel{}{\to }\text{R}\text{e}+\text{H}\text{e}$

Concept introduction:

In an atom, three sub-atomic particles are present which are arranged in a certain way to make the atom stable. The nuclear attraction force works between electrons and protons due to opposite charges. The force between protons and neutrons holds these particles together. It can be measured by measuring the amount of energy necessary to break these forces.

It can be calculated with the help of Einstein’s mass − energy equation:

$\text{ΔE= }\Delta {\text{m × c}}^{\text{2}}$

The mass defect ( $\Delta \text{m}$ ) can be calculated as the difference in the atomic mass and the sum of masses of all atomic particles.