# If a gold atom has a diameter of 2.70xx10^-10*m, how many gold atoms are required to form a monolayer that spans a distance of 7.0xx10^-3*m?

And thus, $\text{number of gold atoms}$
$= \frac{7.0 \times {10}^{-} 3 \cdot m}{2.70 \times {10}^{-} 10 \cdot m} = 2.60 \times {10}^{7}$ $\text{gold atoms}$.