 Peak  Trough  Amplitude  Wavelength ( ) (in meters)  Frequency measured in Hertz: (Hz): cycles per second

 Speed of a wave = wavelength * frequency  v= f  Increased frequency has increased energy  for Electromagnetic waves: ◦ Speed = 3.0x10 8 m/s(speed of light) ◦ c = 3.0x10 8 m/s

Rabid Monkeys InIn Violet Underpants eXterminate Gibbons Radio Waves Microwaves Infrared Visual Light Ultra Violet X-Ray Gamma Ray Large Small Small f Large f Low NRG High NRG

 Range of wavelengths in the visible spectrum 7.5 x m 4 x m 750nm400nm ROYGBIVROYGBIV

ColourWavelength IntervalFrequency range (Hz) Red~ 630–750 nm (10 14 ) Orange~ 590–630 nm5.09 – 4.76 (10 14 ) Yellow~ 560–590 nm5.36 – 5.08 (10 14 ) Green~ 490–560 nm6.12 – 5.36 (10 14 ) Blue~ 450–490 nm6.67 – 6.12 (10 14 ) Indigo~ 435–450 nm6.90 – 6.67 (10 14 ) Violet~ 400–450 nm7.5 – 6.67 (10 14 )

 All colours added together

 Continuous Colour Spectrum A line spectrum consists of distinct bright lines appearing on a dark background that occur in different parts of the visible spectrum.

 An atom excited by addition of energy (heat) will send off electron(s) from its orbital. As the electron returns, it emits electromagnetic waves, and can be seen as coloured light.  P.143

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