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Light is an electromagnetic wave. Turn text to image. Illustrate the meanings of the ideas in the following paragraphs to show how accelerating charges produce electromagnetic waves or EMR, electromagnetic radiation. Use images, examples, and make reference to useful pages in your text and to helpful websites! When an electron in an atom absorbs energy, it can transition to a higher energy level. It will then transition down to a lower, more stable energy level. In downtransitioning, the electron must give up some of its energy, it gives up that energy in the form of a photon, or an amount of radiant energy. That energy travels in the form of an electromagnetic wave. The electromagnetic wave is the result of interactions between oscillating electric and magnetic fields emanating from the moving charge. The electron has an electric field with field lines which end on the charge. The motion of the electron induces a closed loop magnetic field perpendicular to its motion. The moving electron therefore has an associated electric and magnetic field. The electric and magnetic fields travel out from the moving charge in all directions, transferring the energy lost by the falling electron. The electric and magnetic fields oscillate in phase and perpendicular to each other and to the direction of motion of the electron. Together, they form the electromagnetic wave emanated from the electron. The electromagnetic wave is the light produced by the accelerating charge. Electromagnetic waves are classified by their wavelength and frequency. The set of all electromagnetic wave wavelengths possible is called the electromagnetic spectrum. Electromagnetic waves may have different wavelength and frequency but all have the same behavior and all travel at c, the speed of light, in a vacuum, such as empty space. Large downtransitions by electrons produce large emissions of energy which result in high energy photons associated with short wave, high frequency light, such as X-rays and UV light. Smaller downtransitions produce smaller or less energetic emissions which result in lower energy photons of visible light, IR, and radio and microwaves. We call electromagnetic waves of between 400nm and 750nm wavelength “visible light” because we can see them. We can see these wavelengths because they stimulate our retina nerve cells to send nerve impulses to the visual processing center of the brain. Other wavelengths do not stimulate those nerve cells, so we do not see those wavelengths.