Question

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number () of the yellow light.

Answer 1

From the expression,

We get,

…….. (i)

Where,

ν = frequency of yellow light

c = velocity of light in vacuum = 3 × 10⁸ m/s

λ = wavelength of yellow light = 580 nm = 580 × 10^–9 m

Substituting the values in expression (i):

Thus, frequency of yellow light emitted from the sodium lamp

= 5.17 × 10¹⁴ s^–1

Wave number of yellow light,