1. Electromagnetic Radiation

2. Electromagnetic Waves Changing electric and magnetic fields can transmit energy across empty space Energy produced is electromagnetic radiation

3. Speed, Wavelength, and Frequency of EM Radiation c (speed of light) = 3.00 x 10 8 m/s c = λf as wavelength increases, frequency decreases and vice versa

4. The Electromagnetic Spectrum Range of wavelengths Logarithmic scale because it spans such a large range of values

5. Radio Waves Radio, television, cell phones Transducers—convert sound into electrical signals FM—frequency modulated (shorter) AM—amplitude modulated

6. Microwaves Telecommunication—satellites Microwave oven

7. Infrared Radiation Thermal radiation –Electric heater –Infrared thermometer –Remote control

8. Visible Light Eyes detect these waves ROYGBIV White light—mixture of all of the colors of the visible spectrum See color when that wavelength is reflected

9. Ultraviolet Radiation Sunlight Ozone molecules absorb most Water purifiers Sterilizing instruments

10. X Rays High energy Medicine Airport security

11. Gamma Rays Produced by nuclear reactions and by radioactive nuclei Medical uses

12. The Photoelectric Effect Photons—bundles of energy Planck’s constant –Energy of a photon is proportional to the frequency of the electromagnetic radiation. Planck’s constant is that proportionality. –h = 6.626176 x 10 -34 J s –E photon = h c/λ

13. The Photoelectric Effect Work function –The energy required to “break” an electron out of a metallic surface—Φ Hf = Φ + KE e –Photon energy (speed of light/wavelength) = work function + kinetic energy