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standard: 1i, 1jterms: p.117article: 144mastering concept: 146(30-38)practice prblems: 121(1-4), 124(5-6lab write up: 125home lab:954 #5 Homework cornell notes: 5.1sec. assessment: 126 (7-11)mastering problems: 147(65-76)

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New Terms• Electromagnetic radiation

– A form of energy that has wavelike behavior• Wavelength

– The shortest distance between equivalent points on a wave

• Frequency– The # of waves that pass through a given point per

second

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relationship

• Wavelength vs. frequency– As wavelength increase, frequency decrease

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• Electromagnetic spectrum– All forms of electromagnetic radiation

• Quantum– The minimum amount of energy that can be

gained or lost by an atom • Planck’s constant

– Value used to determine the energy of a quantum

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• Photoelectric effect – phenomenon where electrons are emitted from a

metal’s surface when light of a certain frequency shines on the surface.

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Sunlight takes about 8 minutes 17 seconds to travel the average distance from the surface of the Sun to the Earth.

Exact values: 299,792,458 meters per second

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Calculating wavelength of an EM waveRadio waves are used to transmit information on various channels. What is the wavelength of a radio wave having the frequency of 5.40 X 1010 Hz? V = 5.40 X 1010 HzC = 3.00 X 108 m/sλ = ? mC = λV λ = C/V = 3.00 X 108 m/s 5.40 X 1010 1/s = 5.5 x 10-3 m

1/s or s-1

3.00 Exp or EE 8 ÷ 5.40 Exp or EE 10 =

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Practice Problems: P. 121 (1-4)1. What is the frequency of green light, which

has a wavelength of 4.9 x 10-7m?2. An X ray has wavelength of 1.15 x 10-10m.

What is its frequency?3. What is the speed of an electromagnetic wave

that has a frequency of 7.8 x 106 Hz?4. A popular radio station broadcasts with a

frequency of 94.7 MHz. What is the wavelength of the broadcast? (1MHz = 106 Hz)

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Calculating wavelength of an EM wave1. What is the frequency of green light, which

has a wavelength of 4.9 x 10-7m?C = 3.00 X 108 m/sλ = 4.9 x 10-7mV = ?

C = λV V = C/λ = 3.00 X 108 m/s 4.9 x 10-7m= 6.12 x 1014 1/s

3.00 Exp or EE 8 ÷ 4.90 Exp or EE -/+ 7 =

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Calculating wavelength of an EM wave2. An X ray has wavelength of 1.15 x 10-10m. What is its frequency?C = 3.00 X 108 m/sλ = 1.15 x 10-10mV = ?

C = λV V = C/λ = 3.00 X 108 m/s 1.15 x 10-10m= 2.61 x 1018 1/s

3.00 Exp or EE 8 ÷ 1.15 Exp or EE -/+ 10 =

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Your Turn...3. What is the speed of an electromagnetic wave that has a frequency of 7.8 x 106 Hz?

C = 3.00 X 108 m/s

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Your Turn...4. A popular radio station broadcasts with a frequency of 94.7 MHz. What is the wavelength of the broadcast? (1MHz = 106 Hz)C = 3.00 X 108 m/sV = 94.7 MHz (106 Hz = 1MHz )=9.47 x 107 s-1 λ = ?C = λV λ= C/V = 3.00 X 108 m/s 9.47 x 107 s-1 = 3.17 m

3.00 Exp or EE 8 ÷ 9.47 Exp or EE -/+ 7 =

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Flame Test Lab 125

• Gamma • Radio

Visible EM Radiation

• The human eye can detect EM radiation within a 400 nm – 750 nm range.

• This radiation is processed and interpreted by our brains as color.

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Element

Color λ (nm)

λ (m) 1m=109nm

V =C/λ C=3x108

E = hv h=6.626x 10-34

Barium Ba Yellow 590

Copper Cu Green/blue

520

Sodium Na orange 630

Calcium Ca

Red/ Orange

620 6.2x10-7 4.8x1014 3.2x10-19

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Element Color λ (nm)

λ (m) 1m=109nm

V =C/λ C=3x108

E = hv h=6.626x 10-34

Lithium Red

Sodium Yellow

Potassium violet

Calcium Red/ Orange

620 6.2x10-7 4.8x1014 3.2x10-19

Strontium Bright red

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Practice Problems: 124(5-6)

5. What is the energy of each of the following types of radiation?

a. 6.32 x 1020 s-1

b. 9.50 x 1013 Hzc. 1.05 x 1016 s-1

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Practice Problems: 124(5-6)5. What is the energy of each of the following

types of radiation? 6.32 x 1020 s-1

v = 6.32 x 1020 s-1

h = 6.626 X 10-34 J.s? J

Ephoton = hV

Ephoton = 6.32 x 1020 s-1 (6.626 X 10-34 J.s)

= 4.19 x 10-13 J

6.32 Exp or EE 20 x 6.626 Exp or EE -/+ 34=

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Practice Problems: 124(5-6)a. 5. What is the energy of each of the

following types of radiation? 9.50 x 1013 Hzv = 9.50 x 1013 s-1

h = 6.626 X 10-34 J.s? J

Ephoton = hV

Ephoton = 9.50 x 1013 s-1 (6.626 X 10-34 J.s)

= 6.29 x 10-20 J

9.50 Exp or EE 13x 6.626 Exp or EE -/+ 34=

1/s or s-1

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Practice Problems: 124(5-6)6. Use Figure 5-5 to determine the types of radiation

described in problem 5a. 6.32 x 1020 s-1 b. 9.50 x 1013 Hzc. 1.05 x 1016 s-1