2) When light of wavelength 311 nm is shone onto the surface of a particular metal in a vacuum, it is found that a reverse voltage (stopping potential) of 0.6

Vis needed to prevent current flow between the photoemitter and an anode connected externally to it. Calculate the work function of the metal in electron volts(ev) and the most likely energy level (i.e. which orbit) the electrons were ejected from.