| A | B |
|---|
| Light | A type of radiant energy you can see. |
| Wavelength | The distance between the crest of one wave and the crest of the next. |
| Frequency | The rate at which waves pass by a point each second. |
| Crest | The high point of a light wave. |
| Trough | The low point of a light wave. |
| Intensity | The brightness of light. |
| Electromagnetic Spectrum | The arrangement of radiant energy by wavelengths and frequencies. |
| Radio and Television Waves | Longest wavelengths; lowest frequencies. |
| Gamma Rays | Shortest wavelengths; highest frequencies. |
| Microwaves | Used to cook foods. |
| Infrared Waves | Used in a toaster. |
| Ultraviolet Waves | Come from the sun; can cause sunburn. |
| X-Rays | Can pass through skin; used by doctors. |
| Light Waves Travel | In straight lines; and in all directions. |
| Shadow | The absence of light because light does not curve around the object. |
| A bigger shadow forms | when an object is closer to the source. |
| A smaller shadow forms | when an object is farther away from the source. |
| Transmitted Light | Light that passes through matter (air, gases, most liquids, some solids. |
| Reflected Light | Light that is bounced off a surface. |
| Absorbed Light | Light that is trapped by matter; often creates warmth. |
| Refracted Light | The change in direction of light when it passes from one kind of matter to another; seems "bent." |
| Regular reflection | An image obtained when light strikes a smooth and shiny surface. |
| Irregular reflection | Produced when light strikes a rough or uneven surface and scatters the light. |
| Plane Mirror | A flat mirror; light is refracted at the same angle as it strikes. |
| Concave Mirror | The reflecting surface curves inward; makes a larger image. |
| Convex Mirror | The reflecting surface curves outward; makes a smaller image. |
| Convex Lens | Thicker in the middle than on the edges; light passes through and comes together to form a bright spot before branching out again. |
| Concave Lens | A lens that is thinner in the middle than on the edges; light passes through and branches out. |
| Real image | An image that is formed on a surface. |
| Magnifier, Camera, and Human Eye | Have a convex lens. |
| Eyeglasses for Nearsightedness | Are made w/ concave lenses. |
| Eyeglasses for Farsightedness | Are made w/ convex lenses. |
