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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. |