Answer
$K=7\times 10^2\frac{N}{m}$
Work Step by Step
We can find mass $m$ as:
$m=\frac{0.108}{6.02\times10^{23}}=1.8\times 10^{-25}$ kg
We know that:
$f=\frac{1}{2\pi}\sqrt\frac{K}{m}$
This simplifies to:
$K=(2\pi f)^2\times m$
We plug in the known values to obtain:
$K=(2\times3.1416\times 10^{13})^2\times 1.8\times 10^{-25}$
$K=7\times 10^2\frac{N}{m}$
