1 / 19

Section 5.1

Section 5.1. Light and Quantized Energy. Objectives. Compare the wave and particle models of light Define a quantum of energy and explain how it is related to an energy change of matter Contrast continuous electromagnetic spectra and atomic emission spectra. Light and Quantized Energy.

berny
Télécharger la présentation

Section 5.1

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. Section 5.1 Light and Quantized Energy

  2. Objectives • Compare the wave and particle models of light • Define a quantum of energy and explain how it is related to an energy change of matter • Contrast continuous electromagnetic spectra and atomic emission spectra

  3. Light and Quantized Energy • Wave Nature of Light • Electromagnetic radiation (ER)form of energy that exhibits wavelike behavior as it travels through space. • Exs: visible light, microwaves, x-rays

  4. Characteristics of waves • Wavelength, :shortest distance between equivalent points on a continuous wave. • Usually in nm • Frequency, : number of waves that pass a given point per second. • Hz (Hertz)

  5. Continued • Amplitude: wave’s height from the origin to a crest, or from the origin to a trough. • Speed of light = c = 3.0x108 m/s

  6. Light and Quantized Energy

  7. Electromagnetic Spectrum • Continuous spectrum of different types of ER. • No portion that does not correspond to a unique wavelength and frequency.

  8. Light and Quantized Energy

  9. Light and Quantized Energy • Calculating wavelength/frequency • Example P.121

  10. Particle Nature of Light • Besides having wave characteristics, light also acts like a particle. • The Quantum Concept: Energy can only be gained or lost in a specified amount  Quantum • Equantum = hν • h is Plank’s Constant = 6.626 x 10-34 J•s

  11. Blocks and Quanta • Think of energy transfer like building a wall of Legos®. • Only add/take away 1 Lego. • No ½ Lego.

  12. Photoelectric Effect • Electrons, called photoelectrons, emit from a metal’s surface when light of a certain frequency shines on the surface. Light Photoelectrons

  13. The Photon • Photon: • particle of electromagnetic radiation • no mass • carries a quantum of energy • Ephoton = hv

  14. Neon Signs

  15. Atomic Emission Spectra • Electricity passed through a tube of gas • Gas atoms absorb energy and become excited • Atoms release the energy absorbed as light.

  16. Atomic Emission Spectra Hydrogen (H) Helium (He) Oxygen (O) http://astro.u-strasbg.fr/~koppen/discharge/index.html

  17. Atomic Emission Spectra Neon (Ne) Xenon (Xe) http://astro.u-strasbg.fr/~koppen/discharge/index.html

  18. Example Problem 5-2 p. 124

  19. Homework • Wave and Energy Worksheet

More Related