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What is it?. The electromagnetic (EM) spectrum is the complete spectrum or continuum of light including radio waves, infrared, visible light, ultraviolet light, X-rays and gamma rays An electromagnetic wave consists of electric and magnetic fields which vibrates thus making waves. Waves.
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What is it? • The electromagnetic (EM) spectrum is the complete spectrum or continuum of light including radio waves, infrared, visible light, ultraviolet light, X-rays and gamma rays • An electromagnetic wave consists of electric and magnetic fields which vibrates thus making waves. The Electromagnetic Spectrum
Waves • Properties of waves include speed, frequency and wavelength • Velocity (v), frequency (f) and wavelength (l) are related in the formula v = lf • All light travels at a speed of 3 x 108 m/s in a vacuum The Electromagnetic Spectrum
Wavelength, Frequency and Energy • Since all light travels at the same speed, wavelength and frequency have an indirect relationship. • Light with a short wavelength *high frequency * high energy • Light with a long wavelength *low frequency. *low energy The Electromagnetic Spectrum
Radio waves • Low energy waves with long wavelengths • Includes FM, AM, radar and TV waves • Low frequency • Used in many devices such as remote control items, cell phones, wireless devices, etc. The Electromagnetic Spectrum
Microwaves • Shorter than radio, longer than light and infrared • First used in radar, now used in communication, xm radio (sirius), medicine and consumer use (microwave ovens) The Electromagnetic Spectrum
Invisible electromagnetic waves that are detected as heat Can be detected with special devices such as night goggles Used in heat lamps Higher energy than microwaves but lower than visible light Infrared waves The Electromagnetic Spectrum
Visible Light • The portion of the electromagnetic spectrum that human eyes can see • ROY G BIV (red, orange, yellow, green, blue, indigo, violet) • Red is the lowest frequency and violet is the highest frequency The Electromagnetic Spectrum
Ultraviolet waves • Higher energy than light waves • Can cause skin cancer and blindness in humans • Used in tanning beds and sterilizing equipment The Electromagnetic Spectrum
X-Rays • High energy waves • Used in medicine, industry and astronomy • Can cause cancer The Electromagnetic Spectrum
Gamma rays • Generated by radioactive atoms and in nuclear reactions • Highest energy • Blocked from Earth’s surface by atmosphere The Electromagnetic Spectrum
Time to think….. 1. What is the relationship between frequency and wavelength? 2. What is meant by ‘spectrum’? 3. What does ROY G BIV mean? 4. Can you actually see x-rays? • Support your answer. The Electromagnetic Spectrum
Now, let’s really think • 5. Which color is has more energy, red or yellow? • 6. Which type of wave travels faster, gamma or radio? • 7. Give an example of how the metric system is used in the electromagnetic spectrum. • 8. Which carries more energy: Microwaves or Radio waves? The Electromagnetic Spectrum
Think about it…. • You have just been involved in a traffic incident that leaves you stranded on the side of the road. Which part of the electromagnetic spectrum would be of the most use to you and why? The Electromagnetic Spectrum