| A | B |
|---|
| electromagnetic wave | a wave that can travel through space or matter and consists of changing electric and magnetic fields |
| perpendicular | at right angles |
| photon | a tiny "packet" of energy that is released by an electron that moves to a lower energy level in an atom |
| radiation | the transfer of energy through matter or space as electromagnetic waves, such as visible light and infrared waves |
| electromagnetic spectrum | the entire range of electromagnetic waves |
| radio waves | EM waves with long wavelengths and low frequencies |
| microwaves | EM waves that are between radio waves and infrared waves in the electromagnetic spectrum |
| infrared waves | EM waves that are between microwaves and visible light in the electromagnetic spectrum |
| visible light | the very narrow range of wavelengths and frequencies in the electromagnetic spectrum that humans can see |
| ultraviolet light | EM waves that are between visible light and X rays in the electromagnetic spectrum |
| gamma rays | EM waves with very high energy and no mass or change; they are emitted by the nucleus of a radioactive atom |
| X rays | high-energy EM waves that are between ultraviolet light and gamma rays in the electromagnetic spectrum |
| law of reflection | the law that states that the angle of incident is equal to the angle of reflection |
| reflection | the bouncing back of a wave after it strikes a barrier or an object |
| absorption | the transfer of energy carried by light waves to particles of matter |
| refraction | the bending of a wave as it passes at an angle from one medium to another |
| scattering | the release of light energy by particles of matter that have absorbed energy |
| constructive interference | interference that results in a wave that has a greater amplitude than that of the individual wave |
| destructive interference | interference that results in a wave that has a smaller amplitude than that of the individual wave |
| diffraction | the bending of waves around a barrier or through an opening |
| interference | a wave interaction that occurs when two or more waves overlap |
| transmission | the passing of light through matter |
| opaque | the term describing matter that does not transmit any light |
| translucent | the term describing matter that transmits light but also scatters the light as it passes through the matter |
| transparent | the term describing matter through which light is easily transmitted |
| pigment | a material that gives a substance its color by absorbing some colors of light and reflecting others |
| primary colors of light | red, blue, and green; these colors of light can be combined in different ratios to produce all colors of light |
| primary pigments | yellow, cyan, and magenta; these pigments can be combined to produce any other pigment |
| secondary color | cyan, magenta, and yellow; a color of light produced when two primary colors of light are added together |
