CEM 141 Lecture Notes - Lecture 14: Electromagnetism, Radiant Energy, Photon
Document Summary
Shorter wavelengths (with high frequencies) are higher in energy than longer wavelengths (with lower frequencies) Problem: light as a wave doesn"t explain all phenomena. When light is shone on metal, sometimes electrons are ejected. Many metals emit electrons when electromagnetic radiation shines on the surface. The light is transferring energy to the electrons at the metal surface where it is transformed into kinetic energy that give the electrons enough energy to leave the atoms in the metal. Uses photomultipliers, photocells, garage door openers light e. Why does adding energy in the form of light (em radiation) allow electrons to. Escape ? (what is keeping them on the atoms?) Attraction through the electromagnetic force keeps the atoms in place. Light energy brings energy into the system. When short wavelength (high energy) light shines on a metal surface electrons are emitted creating a measurable current.
