1. The Nature of Light The Electromagnetic Spectrum

2. Light & Electromagnetism Light- is it a wave? Or a particle? When passed through 2 slits – interference pattern. Must be a wave. BUT… when light strikes a piece of metal… electrons may fly off. ?? Why?? The Photoelectric effect- Light also exists as packet/particles of energy called PHOTONS. http://www.lewport.wnyric.org/mgagnon/Photoelectric_Effect/photoelectriceffect1.htm IT’S A WAVE AND A PARTICLE! A wavicle!

3. Light- as an electromagnetic wave. The energy of light is proportional to frequency. The speed of light depends on the medium. Brightness depends on intensity.

4. Sunlight contains ultraviolet light. X rays & gamma rays are used in medicine. Infrared light can be felt as warmth. Microwaves are used in cooking and communication. Radio waves are used in communications and radar.

5. Visible Light (white light) This is the light our eyes can detect!

6. Seeing Color Different wavelengths of light correspond with different colors. However… things do not emit their own light… they reflect light. so, if something looks BLUE… it is actually only reflecting the blue wavelength back at you and absorbing the others.