1 / 15

Waves and Particles: Electrons in Atoms

Explore the concept of waves and particles, wavelengths and frequencies, and the energy of photons in the electromagnetic spectrum. Learn about quantum theory and the wave-particle duality.

cynthiaray
Download Presentation

Waves and Particles: Electrons in Atoms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. I. Waves & Particles(p. 117-124) Ch. 5 - Electrons in Atoms C. Johannesson

  2. A. 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 C. Johannesson

  3. crest A A origin trough  A. Waves greater amplitude (intensity) greater frequency (color) C. Johannesson

  4. B. EM Spectrum HIGH ENERGY LOW ENERGY C. Johannesson

  5. R O Y G. B I V red orange yellow green blue indigo violet B. EM Spectrum HIGH ENERGY LOW ENERGY C. Johannesson

  6. B. EM Spectrum • Frequency & wavelength are inversely proportional c =  c: speed of light (3.00  108 m/s) : wavelength (m, nm, etc.) : frequency (Hz) C. Johannesson

  7. WORK:  = c   = 3.00  108 m/s 4.34  10-7 m B. EM Spectrum • EX: Find the frequency of a photon with a wavelength of 434 nm. GIVEN:  = ?  = 434 nm = 4.34  10-7 m c = 3.00  108 m/s = 6.91  1014 Hz C. Johannesson

  8. B. EM Spectrum • What happens to the frequency if the wavelength is shorter? • Try calculating the frequency if the wavelength is 405nm. C. Johannesson

  9. C. Quantum Theory • Planck (1900) • Observed - emission of light from hot objects • Concluded - energy is emitted in small, specific amounts (quanta) • Quantum - minimum amount of energy change C. Johannesson

  10. Classical Theory Quantum Theory C. Quantum Theory • Planck (1900) vs. C. Johannesson

  11. C. Quantum Theory • Einstein (1905) • Observed - photoelectric effect C. Johannesson

  12. C. Quantum Theory • Einstein (1905) • Concluded - light has properties of both waves and particles “wave-particle duality” • Photon - particle of light that carries a quantum of energy C. Johannesson

  13. C. Quantum Theory • The energy of a photon is proportional to its frequency. E: energy (J, joules) h: Planck’s constant (6.6262  10-34 J·s) : frequency (Hz) E = h C. Johannesson

  14. C. Quantum Theory • EX: Find the energy of a red photon with a frequency of 4.57  1014 Hz. GIVEN: E = ?  = 4.57  1014 Hz h =6.6262  10-34 J·s WORK: E = h E = (6.6262  10-34 J·s) (4.57  1014 Hz) E = 3.03  10-19 J C. Johannesson

  15. C. Quantum Theory • Violet light has a frequency of 7.41x1014Hz, does it have more or less energy than red light? C. Johannesson

More Related