Chapter 3.1, Problem 3.3BFP

Interpretation Introduction

Interpretation:

The number of copper atoms in a penny is to be calculated. The road map for the calculation of the copper atoms is to be included.

Concept introduction:

The SI unit for amount of substance is $\text{mol}$. One mole is defined as the amount of substance that contains the same number of entities such as molecules, ions, atoms as the number of atoms in $12\text{ g}$ of $\text{C-12}$. This number is called Avogadro’s number. The value of Avogadro’s number is $\text{6}\text{.022}\times {\text{10}}^{23}\left(\text{entitites/mol}\right)$.

The number of atoms of a substance can be calculated from the given mass of a substance, its molar mass, and the Avogadro’ number.

The expression to calculate the number of atoms of a substance when the mass of the substance in grams is given is as follows:

$\text{Number of atoms}=\left(\text{Mass }\left(\text{g}\right)\right)\left(\frac{1\text{ mol}}{\text{no}\text{. of grams}}\right)\left(\frac{6.022\times {10}^{23}\text{ atoms}}{1\text{ mol}}\right)$