Crest Trough Amplitude – half the height

2. Waves • Crest • Trough • Amplitude – half the height • Wavelength – distance from one point on one wave to the same point on an adjacent wave • Frequency – Number of times a wave passes a point in one second (Hertz)

4. Waves • Frequency & Wavelength – • Frequency & Energy – • Wavelength & Energy – • Amplitude & Energy -

11. How many complete waves are shown above? • What is the wavelength of light shown above?

13. Blu-Ray = 405 nanometers (blue light) DVD = 650 nanometers (red light)

14. Calculate the number of complete wavelengths for each wave shown to the left. • Calculate the wavelength of each wave. • 1 nm = 1 X 10-9 m. Convert each wavelength to nm. • Which of the waves would be in the visible range?

15. Light • All electromagnetic radiation moves at speed of light (186,000 mi/s or 3 X 108 m/s) • All EM radiation is a form of light • Visible light = 400 nm to 700 nm violet red

16. The Electromagnetic Spectrum Light Safe radiation (non-ionizing) Dangerous (ionizing) Produced by nuclear decay

19. Microwaves Traditional Heat – increase translational motion of water Microwaves – increase rotational motion of water

20. Traditional Heat Microwaves

24. Light

27. c = ln c = speed of light (3 X 108 m/s) l = wavelength (meters) • = frequency (Hz or s-1) Important conversion 1 nm = 1 X 10-9 m

28. Calculate the wavelength of a 60 Hz EM wave 5 X 106 m

29. Calculate the wavelength of a 98.5 MHz FM radio station 3.05 m

30. Calculate the frequency of 500 nm blue light. 6 X 1014 s-1

31. Light 6. Wave-Particle Duality a. light can be viewed as both a wave and a particle b. Max Planck/Einstein ~1910 c. Photon – has no mass, only energy

32. Light

33. E = hn (for one photon) E = Energy (J) h = 6.63 X 10-34 J s (Planck’s constant) n = frequency (Hz)

34. Calculate the energy of laser light with a frequency of 4.69 X 1014 s-1 . Ans: 3.11 X 10-19 J (This is for one photon)

35. Calculate the energy of a photon of wavelength 600 nm. ANS:3.3 X 10-19 J

36. Calculate the energy of a photon of wavelength 450 nm (blue light). Ans: 4.42 X 10-19 J (This is for one photon)

37. A single photon has an energy of 3.616 X 10-19 J. • Calculate the frequency of the photon. • Calculate the wavelength of a photon in meters • Calculate the wavelength of a photon in nanometers. • Is this photon in the visible range? • What range of the spectrum would you expect a photon of 800 nm to be? • Calculate the energy for one mole of photons with energy of 3.616 X 10-19 J.

38. 5.45 X 1014 Hz • 5.50 X 10-7 m • 550 nm • Yes • IR • 3.616 X 10-19 J X 6.02 X 1023 photons 1 photon 1 mole =2.18 X 105 J/mol

39. My l = 8.1 X 10-36 m at 3 mph

41. Bohr Model • Neils Bohr Planetary Model • Studying line spectra of elements • Only certain lines are present (quantized) • Not a rainbow • Spectra are a fingerprint for atoms/molecules (Astronomy)

43. Quantized – only certain orbits exist (rest is forbidden zone)

46. Bohr Model 4. Ways to make something glow Photon AbsorptionCollision -Glow in the dark -Heat -Electricity -Chemical Reaction

47. Photon AbsorptionCollision

50. Quantum Mechanical Model Electron as a particle Heisenberg Uncertainty Principle – can never know both the position and velocity of an electron at the same time