Question

Mass of a photon is given by 3.313 x 10^-34 kg. Find it’s wavelength.

(a) 0.67A°

(b) 0.67nm

(c) 0.37A°

(d) 1.67A°

The question was posed to me during an interview.

Question is from Towards Quantum Mechanical Model of the Atom topic in section Structure of Atom of Chemistry – Class 11

Answer 1

Correct answer is (a) 0.67A°

The best explanation: Louis de Brogie gave the realation between momentum and wavelength as λ = h/p. Here h is Planck’s constant, whose value is 6.626 x 10^-34 J/s. Wavelength = h/mc = 6.626 x 10^-34 Js/(3.313 x 10^-34 kg x 3 x 10^8 m/s) = 0.67A°.