Chapter 20, Problem 20.14A

Interpretation Introduction

Interpretation:

The mass lost in grams needs to be determined, when coal and methane are used to produce energy. The average household uses $\text{3}{\text{.9 × 10}}^{\text{7}}\text{kJ}$ of energy per year.

${\text{CH}}_{\text{4}}{}_{\text{(g)}}{\text{ + 2 O}}_{\text{2(g)}}\stackrel{}{\to }{\text{ CO}}_{\text{2}}{}_{\text{(g) }}{\text{ + 2 H}}_{\text{2}}{\text{O}}_{\text{(g)}}\text{ ΔE = - 3}{\text{.9 × 10}}^{\text{7}}\text{kJ}$

Concept introduction:

In an atom, three sub-atomic particles 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:

${\text{ΔE= m × c}}^{\text{2}}$

Here, m is mass and c is speed of light.