Question

does anyone know wy when an elctron is ejected from an atom it'e kinetic enegy is not the workfunction plus the foton absorved?

Answer 1

The photon's energy, less the work function, is the max possible kinetic energy. But the electron may lose some kinetic energy getting away from the material it was ejected from. For example, perhaps it comes from a bit below the surface, and it loses some kinetic energy getting away. By the time the electron's energy is measured, it is less.

At least that's the way it was explained to me! No personal experimental knowledge.