The theory I have read When you charge an electroscope with a negatively charged rod, electrons are repelled to the bottom of the electroscope and the gold leaf rises. Then when you shine light above the fundamental frequency on the top plate of the electroscope, electrons are liberated from the plate and the leaf falls. What I don't understand Where are these electrons liberated too? Where do they go? And are they dragged up from the gold leaf before being liberated somewhere? If they are liberated from the plate itself (too somewhere) then surely the plate will get even more positively charged and therefore the leaf would stay elevated. Am I missing something?