Electrons in the surface of a metal can interact with photons.


1. The Photoelectric Effect

Something to do with photons and electricity. The emission of electrons from a metal surface when illuminated by certain colours of light has long been known about, but explaining why was always a challenge.


2. Einstein's Photoelectric Equation

Following on from the previous video about the photoelectric effect this describes the work function of a material and the threshold frequency, all neatly tidied up in Einstein's photoelectric equation.