As we know that wavelength and frequency is inversely proportional to each other. Greater the wavelength smaller the frequency and vice versa.
Solution:
The relation between wavelength and frequency is as follow,
υ = c / λ
where
υ = frequency = ?
c = velocity of light = 3.0 × 10⁸ ms⁻¹
λ = wavenumber = 542 nm = 542 × 10⁻⁹ m
Putting the given values,
υ = 3.0 × 10⁸ ms⁻¹ / 542 × 10⁻⁹ m
Result:
υ = 5.53 × 10¹⁴ s⁻¹
