When a stationary sodium atom (mass ) absorbs a single photon of wavelength 480 nm
PHYSICS · Multi-part · CBSE · Physics · Dual Nature of Radiation and Matter · Dual Nature of Radiation and Matter
Problem
When a stationary sodium atom (mass 3.82×10−26kg) absorbs a single photon of wavelength 480 nm, it recoils in the opposite direction of the incoming light. Neglect any internal excitation energy of the atom and assume the recoil occurs in free space.
(a) Determine the magnitude of the momentum carried by the photon.
(b) Calculate the speed acquired by the sodium atom due to the absorption.
(c) Compute the kinetic energy of the recoiling atom and express it as a percentage of the photon's original energy. Briefly explain why this percentage is so small.