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science
chapter 9 vocab
| Term | Definition |
|---|---|
| electromagnetic wave | A wave that can transfer electric and magnetic energy through the vacuum of space. |
| electromagnetic radiation | The energy transferred through space by electromagnetic waves. |
| wavelength | The distance between the crest of one wave and the crest of the next wave. |
| frequency | The number of complete waves that pass a given point in a certain amount of time. |
| electromagnetic spectrum | The complete range of electromagnetic waves placed in order of increasing frequency. |
| radio waves | Electromagnetic waves with the longest wavelengths and lowest frequencies. |
| microwaves | Electromagnetic waves that have shorter wavelengths and higher frequencies than radio waves. |
| infrared rays | Electromagnetic waves with shorter wavelengths and higher frequencies than microwaves. |
| visable light | Electromagnetic radiation that can be seen with the unaided eye. |
| ultraviolet rays | Electromagnetic waves with wavelengths shorter than visible light but longer than X-rays. |
| x-rays | Electromagnetic waves with wavelengths shorter than ultraviolet rays but longer than gamma rays. |
| gamma rays | Electromagnetic waves with the shortest wavelengths and highest frequencies. |
| ray | A straight line used to represent a light wave. |
| regular reflection | Reflection that occurs when parallel rays of light hit a smooth surface and all reflect at the same angle. |
| image | A copy of an object formed by reflected or refracted rays of light. |
| diffuse reflection | Reflection that occurs when parallel rays of light hit an uneven surface and all reflect at different angles. |
| plane mirror | A flat mirror that produces an upright, virtual image the same size as the object. |
| virtual image | An upright image formed where rays of light appear to come from. |
| concave mirror | A mirror with a surface that curves inward. |
| optical axis | An imaginary line that divides a mirror in half. |
| focal point | The point at which light rays parallel to the optical axis meet, or appear to meet, after being reflected (or refracted) by a mirror (or a lens). |
| real image | An upside-down image formed where rays of light meet. |
| convex mirror | A mirror with a surface that curves outward. |
| index of refraction | A measure of the amount a ray of light bends when it passes from one medium to another. |
| mirage | An image of a distant object caused by refraction of light as it travels through air of varying temperature. |
| lens | 1. The flexible structure that focuses light that has entered the eye. 2. A curved piece of glass or other transparent material that is used to refract light. |
| concave lens | A lens that is thinner in the center than at the edges. |
| convex lens | A lens that is thicker in the center than at the edges. |