Simple Photoelectric Effect Conceptual Question

[fallen186]

This is more of a conceptual question.

Homework Statement

--------------------
1.$$KE_{Max} = hf-\phi$$

2.$$\phi$$ = Work Function. The minimum energy required to free an electron with a photon

3.$$E=hf$$ This it the energy of a photon
---------------------
In my book it says that" $$hf > \phi$$" then electrons can be ejected" and ""If the light frequency is too low, such that the photon energy $$hf$$ is less than the work function $$\phi$$, then there is simply insufficeient energy in any given photon to free an electron.

What is the kinetic energy of an electron if the energy of a photon is the same as the Work Function? Like what happens?

 

[m.medhat]

the kinetic energy of an electron is zero
Like what happens? !