Presentation is loading. Please wait.

Presentation is loading. Please wait.

Frequency and Wavelength. Waves on the Ocean Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324.

Similar presentations


Presentation on theme: "Frequency and Wavelength. Waves on the Ocean Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324."— Presentation transcript:

1 Frequency and Wavelength

2 Waves on the Ocean

3 Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324

4 Wavelength of a Wave Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324

5 Wavelength of a Wave Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324

6 Visible Spectrum of Light PRISM Slit Ray of White Light Waves 1 / 33,000 ” long Waves 1 / 70,000 ” long R ed O range Y ellow G reen B lue I ndigo V iolet

7

8 Visible Spectrum of Light

9 2 half-wavelengths 3 half-wavelengths 1 half-wavelengths Unplucked string

10 Only certain wavelengths will `fit' into an orbit. If the wavelength is longer or shorter, then the ends do not connect. Thus, deBroglie explains the Bohr atom in that on certain orbits can exist to match the natural wavelength of the electron. If an electron is in some sense a wave, then in order to fit into an orbit around a nucleus, the size of the orbit must correspond to a whole number of wavelengths. n = 6 orbit n = 4 orbit

11 Waves Wavelength ( ) - length of one complete wave Frequency ( ) - # of waves that pass a point during a certain time period –hertz (Hz) = 1/s Amplitude (A) - distance from the origin to the trough or crest Courtesy Christy Johannesson f

12 Waves A greater amplitude (intensity) greater frequency (color) crest origin trough A Courtesy Christy Johannesson

13 The Electromagnetic Spectrum AM radio Short wave radio Television channels FM radio Radar Microwave Radio Waves Gamma Rays X- Raysinfrared Increasing photon energy Increasing frequency Decreasing wavelength Red Orange Yellow Green Blue Indigo Violet UV Rays VisibleLightVisibleLight R O Y G B I V HIGHENERGYHIGHENERGY LOWENERGYLOWENERGY

14 Frequency O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles  1982, page second Frequency 4 cycles/second = 4 hertz 12 cycles/second = 12 hertz 36 cycles/second = 36 hertz

15 AM & FM Waves Carrier frequency Sound pattern Amplitude Modulated carrier Frequency Modulated carrier

16 AM & FM Waves Carrier frequency Sound pattern Amplitude Modulated carrier Frequency Modulated carrier AM - FM Radio

17 Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

18 Electromagnetic Spectrum LOWENERGYLOWENERGY HIGHENERGYHIGHENERGY  rays X-raysUltravioletInfraredMicrowave Radar Radio waves TV FM Short Wave Long Wave Visible spectrum nm nm 10 0 nm10 1 nm10 2 nm cm cm cm 10 0 cm 10 1 cm 1cm 10 1 m10 2 m10 3 m 10 4 m Hz10 18 Hz10 17 Hz Hz Hz10 13 Hz Hz Hz10 10 Hz10 9 Hz 100 MHz 10 MHz1 MHz100 KHz RedOrangeYellowVioletBlueGreen 700 nm 600 nm 500 nm400 nm Wavelength, Frequency, 10 3 nm Hz Electromagnetic spectrum White Light Davis, Frey, Sarquis, Sarquis, Modern Chemistry  2006, page 98

19 Common wavelength units for electromagnetic radiation Picometer pm Gamma ray Ångstrom Å X-ray Nanometer nm X-ray Micrometer  m Infrared Millimeter mm Infrared Centimeter cm Microwave Meter m 10 0 Radio Unit Symbol Wavelength, (m) Type of Radiation Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

20 Waves Low frequency High frequency Amplitude long wavelength  short wavelength 

21 Waves Low frequency High frequency Amplitude long wavelength  short wavelength  60 photons 162 photons low energy high energy

22 Red and Blue Light Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 325 Photons - particle of light that carries a quantum of energy

23 Electromagnetic Radiation Light as a wave Light as a stream of energy (packets of photons) Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 325

24 Wavelength and Frequency E = h c =  c = speed of light (3 x 10 8 m/s) = frequency (s -1 )  = wavelength (m) E = energy (Joules or J) h  = Planck’s constant (6.6 x J/s) = frequency (s -1 ) f f f f “nu” “lambda”

25 Electromagnetic Spectrum Frequency & wavelength are inversely proportional c = c:speed of light (3.00  10 8 m/s) :wavelength (m, nm, etc.) :frequency (Hz) Courtesy Christy Johannesson

26 Electromagnetic Spectrum GIVEN: f = ? = 434 nm = 4.34  m c = 3.00  10 8 m/s WORK: f = 3.00  10 8 m/s 4.34  m f = 6.91  Hz EX: Find the frequency of a photon with a wavelength of 434 nm. Courtesy Christy Johannesson 1 x 10 9 nm 1 m

27 Quantum Theory Max Planck (1900) –Observed - emission of light from hot objects –Concluded - energy is emitted in small, specific amounts (quanta) –Quantum - minimum amount of energy change Courtesy Christy Johannesson Max Planck

28 Bohr Model of Hydrogen Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 331 Nucleus Possible electron orbits e e

29 Continuous vs. Quantized Energy Energy A B Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 330 continuous quantized

30 Continuous vs. Quantized ABAB Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 330

31 Quantum Theory Planck (1900) vs. Classical Theory Quantum Theory Courtesy Christy Johannesson

32 Quantum Theory Albert Einstein (1905) –Observed - photoelectric effect Courtesy Christy Johannesson Albert Einstein

33 Wavelength and Frequency E = h c =  c = speed of light (3 x 10 8 m/s) = frequency (s -1 )  = wavelength (m) E = energy (Joules or J) h  = Planck’s constant (6.6 x J/s) = frequency (s -1 ) f f f f “nu” “lambda”


Download ppt "Frequency and Wavelength. Waves on the Ocean Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324."

Similar presentations


Ads by Google