Question

a crystallographer measures the horizontal spacing between molecules in a crystal. the spacing is 13.7 nm. what is the total width of a crystal in millimeters 10^5 molecules across? write your answer as a decimal.

Explanation:

Step1: Calculate total spacing in nanometers

Multiply the spacing per molecule by the number of molecules. The spacing per molecule is $13.7$ nm and the number of molecules is $10^{5}$. So the total spacing in nm is $13.7\times10^{5}$ nm.
$13.7\times10^{5}=1370000$ nm

Step2: Convert nanometers to millimeters

We know that $1$ mm = $10^{6}$ nm. To convert from nm to mm, divide the total spacing in nm by $10^{6}$.
$\frac{1370000}{10^{6}} = 1.37$ mm

Answer:

$1.37$