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The Electromagnetic

Wavelength//energy

MAP TAP 2003-2004 The 1 Teacher Page

• Content: Physical Science—The Electromagnetic Spectrum • Grade Level: High School • Creator: Dorothy Walk • Curriculum Objectives: SC 1; Intro Phys/Chem IV.A ()

MAP TAP 2003-2004 The Electromagnetic Spectrum 2 MAP TAP 2003-2004 The Electromagnetic Spectrum 3 What is it?

• The electromagnetic spectrum is the complete spectrum or continuum of including waves, , visible light, light, X- rays and gamma rays • An electromagnetic consists of electric and magnetic fields which vibrates thus making waves.

MAP TAP 2003-2004 The Electromagnetic Spectrum 4 Waves

• Properties of waves include speed, frequency and • Speed (s), frequency (f) and wavelength (l) are related in the formula l x f = s • All light travels at a speed of 3 s 108 m/s in a

MAP TAP 2003-2004 The Electromagnetic Spectrum 5 Wavelength, Frequency and Energy • Since all light travels at the same speed, wavelength and frequency have an indirect relationship. • Light with a short wavelength will have a and light with a long wavelength will have a . • Light with short has high energy and long wavelength has low energy

MAP TAP 2003-2004 The Electromagnetic Spectrum 6 MAP TAP 2003-2004 The Electromagnetic Spectrum 7 Radio waves

• Low energy waves with long wavelengths • Includes FM, AM, and TV waves • Wavelengths of 10-1m and longer • Low frequency • Used in many devices such as remote control items, phones, devices, etc.

MAP TAP 2003-2004 The Electromagnetic Spectrum 8 MAP TAP 2003-2004 The Electromagnetic Spectrum 9

• Longer than radio, shorter than light and infrared • Wavelength 1 x 10 - 4 m to 1 x 10-1 m • First used in radar, now used in communication, medicine and consumer use ( ovens)

MAP TAP 2003-2004 The Electromagnetic Spectrum 10 MAP TAP 2003-2004 The Electromagnetic Spectrum 11 Infrared waves

• 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

MAP TAP 2003-2004 The Electromagnetic Spectrum 12 MAP TAP 2003-2004 The Electromagnetic Spectrum 13 Visible Light

• The portion of the electromagnetic spectrum that human eyes can detect • ROY G BIV (, , , , , , ) • Red is the lowest frequency and violet is the highest frequency

MAP TAP 2003-2004 The Electromagnetic Spectrum 14 MAP TAP 2003-2004 The Electromagnetic Spectrum 15 Ultraviolet waves

• Higher energy than light waves • Can cause and blindness in humans • Used in tanning beds and sterilizing equipment

MAP TAP 2003-2004 The Electromagnetic Spectrum 16 MAP TAP 2003-2004 The Electromagnetic Spectrum 17 X-Rays

• High energy waves • First discovered by Roentgen • Used in medicine, industry and • Can cause cancer

MAP TAP 2003-2004 The Electromagnetic Spectrum 18 MAP TAP 2003-2004 The Electromagnetic Spectrum 19 Gamma rays

• Highest energy • Blocked from Earth’s surface by atmosphere

MAP TAP 2003-2004 The Electromagnetic Spectrum 20 MAP TAP 2003-2004 The Electromagnetic Spectrum 21 MAP TAP 2003-2004 The Electromagnetic Spectrum 22 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?

MAP TAP 2003-2004 The Electromagnetic Spectrum 23 Now, let’s really think

• 4. Can you actually see x-rays? – Support your answer. • 5. Which is more energetic, red or yellow? • 6. Which type of wave travels faster, gamma or radio? • 7. Why are microwaves more dangerous than radio waves?

MAP TAP 2003-2004 The Electromagnetic Spectrum 24 Think about it….

• You have just been involved in a traffic incident that you stranded on the side of the road. Which part of the electromagnetic spectrum would be of the most use to you and why?

MAP TAP 2003-2004 The Electromagnetic Spectrum 25 Answers

• 1. Frequency and wavelength are properties of waves and since speed is constant for em waves, as frequency increases, wavelength decreases. • 2. Spectrum is a continuum of all electromagnetic waves • 3, ROY G BIV is the difference of the visible light in order of longest wavelength to shortest wavelength. • 4. X-rays can not be seen, only the waves in the visible light portion are visible. • 5. Yellow is higher energy than red because it has a shorter wavelength and higher frequency. • 6. Both travel at the same speed, 300,000 km/s (all em waves travel at the same speed) • 7. Microwaves have a higher frequency than radio and carry more energy.

MAP TAP 2003-2004 The Electromagnetic Spectrum 26