Explanation:
Given: [tex]\lambda = 8.38\:\text{nm} = 8.38×10^{-9}\:\text{m}[/tex]
Its frequency [tex]\nu[/tex] is defined as
[tex]\nu = \dfrac{c}{\lambda} = \dfrac{3×10^8\:\text{m/s}}{8.38×10^{-9}\:\text{m}}[/tex]
[tex]\:\:\:\:= 3.58×10^{16}\:\text{Hz}[/tex]
