1. Light as a Wave Waves are traveling disturbances that carry energy from one place to another The speed of a wave is calculated by using the equation: V = f · λ Speed = frequency x wavelength

2. Light as a Wave The speed of light is always 3 x 10 8 m/s 300,000,000 m/s This means that frequency and wavelength of light waves have an inverse relationship. [http://www.cartoonstock.com/newscartoons/cartoonists/dbr/lowres/dbrn264l.jpg]

3. [http://www.andor.com/image_lib/lores/introduction/introduction%20(light)/intlight%201%20small.jpg] Light as a Wave

4. Light as a Particle Planck’s Theory Energy that is absorbed or emitted by an object is restricted to “pieces” (quanta) of energy. [http://www.dupre-vermiculite.co.uk/images/refractory.jpg]

5. Light as a Particle Planck’s Equation: E = h · v Energy = Planck’s Constant x frequency Planck’s Constant = 6.6261 x 10 -34 J-s

6. Light as a Particle Photoelectric Effect Some colors of light can cause electrons to eject from the surface of metals. Einstein - light exists as photons that carried energy according to Planck’s equation [http://hyperphysics.phy-astr.gsu.edu/hbase/imgmod2/pelec.gif]

7. Light & The Bohr Model When certain elements are “burned” or electricity is passed through them they create specific colors. Atoms must absorb energy and then release it in the form of light. Click here for a flame test video [http://scripts.mit.edu/~clubchem/gallery/main.php?g2_view=core.DownloadItem&g2_item Id=135&g2_serialNumber=2&g2_GALLERYSID=2e0697a5786c0e9bad5bb7a61f801208]

8. Light & The Bohr Model When the light from these tests is passed through a spectrum, only certain colors appear in the emission line spectrum.

9. Light & The Bohr Model When electrons absorbed energy they would change “orbits” (n=1 to n=2) When the electrons “fell” back to their original orbit, they released the energy as light. [http://www.chemistrydaily.com/chemistry/upload/thumb/d/de/307px-Bohratommodel.png]

10. [http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_09/FG09_12.JPG]

11. Light & The Bohr Model This only worked for Hydrogen! It cannot effectively predict atoms with more electrons. [http://www.incompetech.com/gallimaufry/signs/bohr.gif]

12. Click here for more spectra