When light is shined onto a metal surface, electrons are given off. Below a certain threshold energy, no electrons are produced regardless of the intensity. This is the photoelectric effect, a paradox finally explained by Albert Einstein with his quantum theory of light. With The Photoelectric Effect: Light Energy Demonstration—ChemTopic™ Lab Activity, demonstrate the photoelectric effect using a metal plate attached to a charged electroscope. Available as part of the Atomic and Electron Structure—ChemTopic™ Labs digital collection. Click the Price link for digital collection pricing.