2. Electromagnetic Radiation: Energy that travels through space in the form of a wave

3. Crest Trough Wavelength Frequency, The number of times a wave part passes by a spot in a given amount of time:  x  c

4. Double Slit Experiment By: Thomas Young Interference Pattern: The calling card of a wave!

6. When solid objects are heated, classical physics predicts that there should be a preponderance of higher frequency [shorter wavelength] light given off by the glowing body…but that is not what we see.

7. In order to produce higher frequency radiation, higher amounts of energy are needed. By: Max Planck E = h An amount of energy Planck’s Constant frequency of light 6.6 x 10 -34 J · s …a Quantum (a bundle of energy)

8. What amount of energy is associated with a frequency of light equal to 1.4 x 10 14 Hz (I.R. radiation)? E = h E = (6.6 x 10 -34 J·s)(1.4 x 10 14 /s) E = 9.2 x 10 -20 J

9. The emission of electrons from a metal, when light shines on the metal, can only occur if the frequency of the light is above a certain minimum (i.e. a certain minimum energy) By: Albert Einstein …that means that lights arrives in bundles… photons what Einstein called photons Au e-e-

10. To Review: Write down the speed of light equation x = c Now solve that equation for the frequency = c/ Next, write down the Planck Equation E = h Substitute what frequency is equal to into the Planck Equation E = hc/ Since you also know that E=mc 2, what is mc 2 also equal to? mc 2 = hc/ Now solve for mass. m = hc/c 2 Cancel out the square on the speed of light m = h/c light has a mass!!! (▼apparent)

11. What is the “mass” of a photon of red light? 6.6 x 10 -34 kg m 2 · s s 2 (7 x 10 -7 m)(3.0 x 10 8 m ) s m= m= 3 x 10 -36 kg Light is a particle!!!!! Light is a wave!!!!!!! Light has a dual nature!!!!! Light exhibits DUALITY!!!!