1. EXAM #2 THIS FRIDAY, 10/16 BRING PENCIL, CALCULATOR, AND SHEET OF NOTES (PUT YOUR A00 NUMBER ON IT) CHAPTER 4 OWL ASSIGNMENTS (& FIRST CHAPTER 6 ASSIGNMENT) DUE 10/15 Announcements

2. Wave Review Amplitude Sound = Volume Visible Light = Brightness Wavelength or Frequency Sound = Pitch Visible Light = Color

3. The Electromagnetic Spectrum How does electromagnetic (em) radiation affect molecules? Microwave IR Visible UV X-Rays

4. Frequency (  ) & Wavelength ( ) Electromagnetic waves in vacuum all travel at c, the “speed of light” c= 2.998 x 10 8 m/sec Light acts like a wave (reflects, refracts, interferes, etc.) BUT…

5. Energy is Quantized Light also acts like particles Photon= “Packet” of energy Energy is proportional to Frequency (and ) Planck’s Equation:

6. UV-B Light and DNA Damage