Question

A crystallographer measures the horizontal spacing between molecules in a crystal. The spacing is 12.7 nm. What is the total width of a crystal in millimeters 10^5 molecules across? Write your answer as a decimal

Answer 1

Assuming this spacing is including the molecule, we can multiply it by the total amoutn of molecules across to get the distance, thus, the width of the crystal:

$12.7nm\cdot10^5=12.7\times10^5nm$

"nano" is 10⁻⁹, and "mili" is 10⁻³, so:

$12.7\times10^5nm=12.7\times10^5\times\frac{10^{-9}}{10^{-3}}mm=12.7\times10^5\times10^{-6}mm=12.7\times10^{-1}mm=1.27mm$

So, the crystal has about 1.27 mm of width.