Chapter 17, Problem 73A

A typical atom is around $2\times {10}^{-10}m$ in diameter, while a typical bacterium is about ${10}^{-6}m$ in diameter. How many atoms thick is the typical bacterium?

To determine

The number of atoms present in typical bacterium.

Answer to Problem 73A

The number of atoms present in typical bacterium is 5000.

Explanation of Solution

Given information:

The diameter of typical atom is,

  $d=2\times {10}^{-10}\text{m}$

The diameter of typical bacterium is,

  $D={10}^{-6}\text{m}$

Formula used:

Let $n$ be the number of atoms present in typical bacterium. Then the relation between diameter of typical bacterium and diameter of atom is,

  $D=nd$

  $n=\frac{D}{d}$

Calculation:

Substitute ${10}^{-6}\text{m}$ for $D$ and $2\times {10}^{-10}\text{m}$ for $d$ .

  $\begin{array}{c}n=\frac{{10}^{-6}\text{m}}{2\times {10}^{-10}\text{m}}\\ =5000\end{array}$

Conclusion:

Therefore, the number of atoms present in typical bacterium is $10000$ .