| A | B |
|---|
| Opacity | The extent to which light is blocked |
| Opaque | Light cannot pass through |
| Translucent | Light passes through, but images are not clearly visible through it |
| Transparent | Light passes through, and images are clearly visible through it |
| Regular Reflection | Reflection of light from a smooth surface (reflects an image) |
| Diffuse Reflection | Reflection of light from a rough surface (doesn’t reflect an image) |
| Index of Refraction | Property of light that indicates how much the speed of light is reduced |
| Rods | Cells of retina sensitive to dim light, but not color |
| Cones | Cells of retina sensitive to bright light and color |
| Primary Colors | The three colors that can be mixed to create all other colors |
| Primary Colors of Light | Red, Green, & Blue |
| Primary Colors of Pigment | Magenta, Yellow, & Cyan |
| Pigment | A colored material that is used to change the color of other substances (ex. Paint) |
| White | When all colors of light are reflected to your eyes |
| Black | When all colors are absorbed and none are reflected to your eyes |
| Color Blindness | When people cannot distinguish between certain colors |
| Incandescent Lights | Produce light by making a piece of metal (the filament) in a light bulb very hot |
| Fluorescent Lights | Produce light by electrifying a gas and converting UV light to visible light |
| Light-emitting diodes (LED) | A semiconducting device that emits light when a voltage is applied to it |
| Neon Lights | Produce light by exciting the molecules of neon gas with a stream of electrons |
| Sodium-vapor Lights | Yellow-orange lights used in street lamps, have vaporized sodium metal in them |
| Tungsten-halogen lights | Very bright headlights on cars, have a tungsten filament like incandescent, but the gas is fluorine or chlorine |
| Lasers | Beams of coherent light |
| Coherent Light | Light consisting of only one wavelength travelling in one direction with consistently-spaced crests |
| Polarization | Making light that vibrates in only one plane |
| Holography | Technique that produces a hologram, a complete 3-dimensional photographic image of an object |
| Total Internal Reflection | Complete reflection of light at the boundary between two different materials |
| Scattering | Rays of light get scattered as they pass through a medium |
