(a) State two conditions under… | Physics

Question 1 Report

(a) State two conditions under which photo-electrons can be emitted from the surface of a metal.

(b) List two particle characteristics of electromagnetic waves.

Answer

Answer Details

(a) Conditions for photo-electron emission

The frequency of the incident radiation must be equal to or greater than the threshold frequency of the metal (equivalently, the photon energy \(hf\) must be at least equal to the work function of the metal).
The radiation must actually fall on (illuminate) the metal surface, and the surface must be a metal capable of emission (a clean, suitable emitting surface).

(b) Two particle characteristics of electromagnetic waves

They are emitted and absorbed in discrete packets (quanta) called photons, each carrying energy \(E = hf\).
Each photon carries momentum \(p = \dfrac{hf}{c}\) and can transfer energy to a single electron in a one-to-one collision (as in the photoelectric and Compton effects).

(a) State two conditions under which photo-electrons can be emitted from the surface of a metal. (b) List two particle characteristics of electromagnetic wa...