Start with an explanation and definition of what a photon is. Explain what is meant by "Quantized", and that light energy comes in packets, or quanta, in whole numbers, with a quanta of light being a photon. A video showing Einstein's experiment dealing with the photoelectric effect, and how he used it to expand the theory of light as a particle was introduced for discussion. The photoelectric effect and Einstein's reasoning will be fully discussed in the next class.