B Photoelectric effect

When a photon is absorbed some of its energy is used to free the electron and what is left over is given to the freed electron as kinetic energy. The stopping potential slows the electron down and if the potential is high enough the electrons won't make it to the detector. The value of the potential at which this happens occurs when the work done by the electric field is equal to the kinetic energy. This value is eV xS, so yes V is the potential (or voltage difference).

 

Is that exactly true? Or is there a range of possible leftover energy transferred from the photon to the electron as kinetic, from 0 up to the entire leftover energy? I don't have the textbook with me, but in Serway's "Modern Physics", he mentions a maximum kinetic energy for the freed electron being equal to the leftover photon energy, which implies there are probably other processes which might take away said energy.

 

How to describe the photoelectric effect correctly, you find in

https://www.physicsforums.com/insights/sins-physics-didactics/