1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 1 Exam #1: average=25.5 (73%) Pick up HW #5: due Thursday, March 8 Important: question on slide #11 will be given in class on Tuesday for credit (reading quiz)!!

2. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 2 The Nature of Light (chapter 3)

3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 3 Properties of Light: Wave-like properties: Reflection, refraction, diffraction, interference Electromagnetic “waves” Particle-like properties: Energy carried in bundles we call “photons” Can propagate through a vacuum

4. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 4 “Light” = Electromagnetic Radiation = Photons Different names for the same thing:

5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 5 Wavelength-distance between crests Figure 3.3

6. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 6 1.Wavelength: Distance between peaks 2.Frequency: Number of peaks which pass you per second. 2.Speed of Light: Wavelength times Frequency equals the speed of light. c

7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 7 The Energy of a Photon Frequency and Wavelength

8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 8 The Electromagnetic Spectrum

9. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 9

10. 10 Which photon has the highest energy? a. ultraviolet b. visible c. x-ray d. infrared e. radio Which photon has the longest wavelength? a. ultraviolet b. visible c. x-ray d. infrared e. radio

11. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 11 Rank the following types of radiation is order of increasing 1) wavelength, 2) frequency, and 3) energy: microwave, visible, x-ray, radio, gamma ray, infrared A)gamma ray, x-ray, visible, infrared, microwave microwave, infrared, visible, x-ray, gamma ray B) microwave, infrared, visible, x-ray, gamma ray gamma ray, x-ray, visible, infrared, microwave C) gamma ray, x-ray, visible, infrared, microwave microwave, infrared, visible, x-ray, gamma ray gamma ray, x-ray, visible, infrared, microwave