Answer:
The metal surface becomes more positive as electrons are lost from it.
Explanation:
Let us note that photoelectric effect refers to a phenomenon in which electrons are ejected from a clean metal surface irradiated with light of appropriate frequency. This photon must possess a frequency above the threshold frequency of the metal and its energy must exceed the work function of the metal. When these conditions are met, electrons are emitted from a clean metal surface, having a constant kinetic energy as long as the frequency of the incident photon remains constant.
However, as photoelectric effect progresses and electrons are lost from the metal surface, the metal surface becomes more positive. The more positive the surface, the greater the attraction of the positive surface for the emitted electrons. This reduces the kinetic energy of the emitted photons even though the frequency of incident photons is held constant.
Within a period, the atom size decreases with increasing group number (from left to right), since the nuclear charge and the number of external electrons increase within the period, but the number of shells does not. The electrons are more strongly attracted to the nucleus and are therefore closer to the nucleus.
I don't know but look on the internet or use a calculator