Answer
$f=1.0\times 10^{18}Hz$
Work Step by Step
Velocity, wavelength, and frequency of a wave are related using the formula $$v=f\lambda$$ Solving for the frequency yields $$f=\frac{v}{\lambda}$$ Substituting known values of $v=c=3.0\times 10^8m/s$ and $\lambda=0.30nm=0.30\times 10^{-9}m$ yields a frequency of $$f=\frac{3.0\times 10^8m/s}{0.30\times 10^{-9}m}$$ $$=1.0\times 10^{18}Hz$$
