## Chemistry: Principles and Practice (3rd Edition)

c = $2.997925\times10^{8}ms^{-1}$ ν = $2.47\times10^{20} Hz$ λ = c/ν = $\frac{2.997925\times10^{8}ms^{-1}}{2.47\times10^{20}s^{-1}}$ = $1.21\times10^{-12} m$ = 1.21 pm ( value of the prefix 'pico' is $10^{-12}$ ).