1 / 16

Electromagnetic Radiation An Introduction to Light and Quantized Energy

Electromagnetic Radiation An Introduction to Light and Quantized Energy. Mrs. Nielsen Honors Chemistry. What is Electromagnetic Radiation?. A form of LIGHT energy that exhibits wavelike behavior as it travels through space. What are some examples of electromagnetic radiation?.

litat
Download Presentation

Electromagnetic Radiation An Introduction to Light and Quantized Energy

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. Electromagnetic RadiationAn Introduction to Light and Quantized Energy Mrs. NielsenHonors Chemistry

  2. What is Electromagnetic Radiation? A form of LIGHT energy that exhibits wavelike behavior as it travels through space

  3. What are some examples of electromagnetic radiation?

  4. Electromagnetic Radiation • Energy (Joules, J) • Frequency () = # waves per unit time (waves/second) (Hertz = hz) • Wavelength () = distance between two corresponding points on adjacent waves c =  • c = speed of light = 3.00 x 108 m/sec

  5. ElectromagneticSpectrum Low Energy Low Frequency High Energy High Frequency In increasing energy, ROYGBIV

  6. Electromagnetic Spectrum • 1. Why are plants green? • 2. What makes a material white? • 3. What makes a material black? • 4. Why should you wear white on a hot summer day? • 5. Which of the following variables are directly proportional values? Indirectly proportional? • Frequency • Wavelength • Energy

  7. Practice Problems • What is the frequency of green light, which has a wavelength of 4.90 x 10-7m? • What is the speed of an electromagnetic wave that has a frequency of 7.8 x 106 Hz?

  8. Scientists and Experiments that lead to Quantum Theory

  9. Quantum Concept - 1900 • German physicist Max Planck started to search for WHY light emitted from heated objects. • Found that a QUANTUM is the minimum amount of energy that can be gained or lost by an atom • Matter can gain or lose energy in small specific amounts called quanta

  10. Quantum Concept • Planck showed mathematically that the energy of a quantum is related to the frequency of the emitted radiation. • Equantum = hn • E = energy • h = Planck’s constant = 6.626 x 10-34 J·s • n = frequency

  11. Practice Problems • What is the energy for each of the following types of radiation? • a. 6.32 x 1020 s-1 • b. 9.50 x 1013 Hz • c. 1.05 x 1016 s-1

  12. Photoelectric Effect - 1905 • Photons are emitted from a metal’s surface when light of a certain frequency shines on a surface • Albert Einstein won the Nobel Prize in Physics in 1922 for proposing that electromagnetic radiation has both wavelike and particle like natures. He calculated that the photon energy was: • Ephoton = hn

  13. Electromagnetic RadiationThe Double Slit Experiment

  14. Quantized Energy Levels - 1911 • Niels Bohr studied the HYDROGEN atom emission spectrum • Conclusion: electrons are restricted to certain orbits corresponding to E levels, hence, they are QUANTIZED • Rutherford never explained how e- fill the space surrounding the nucleus

  15. Quantized Energy Levels Ground State – lowest energy state Excited State – Electrons jump to higher energy levels due to an input of energy

  16. Quantized Energy Levels Absorption – Energy absorbed to “boost” e- to higher E level (excited state) Emission – Energy released by e- when “falling” back to lower E level (ground state)

More Related