Question

calculate frequency and wave number of light having wavelength 400nm​

Answer 1

Explanation:

Correct option is

C

0.0025nm−1

Wavenumber of a wave is defined as ν~=λ1, where λ is the wavelength.

Given that wavelength of the photon is λ=400 nm=400×10−9 m

Thus, wave number is ν~=(400)−1 nm−1=0.0025 nm−1