According to my book the mechanism of ionization is: "If an atom absorbs enough energy so that an electron is raised to the highest energy level the electron becomes free of the atom i.e. ionization occurs."
In photoelectric and thermionic emission the same thing takes place: electrons are given energy so that they become free of the atom and are thus emitted. Only the sources of energy are different.
But yet in none of the books I have read is this stated that photoelectric emission is an example or has the same mechanism as ionization. Is photoelectric emission then an example of ionization? If not, why?
Best Answer
Sure, why not? Any process which imparts sufficient energy to the electron to kick it free of the nucleus is an ionization process. Heck, hitting the electron with another particle (while statistically unlikely) counts as ionization.