Bell Work: Spring Break When did you see a reflection? When did you experience constructive interference? When did you see light that had been refracted? Other than visible light, what part of the electromagnetic spectrum did you encounter? In what context?

Electromagnetic Spectrum Dual Nature Can act like a particle (photon) Can act like a wave

Electromagnetic Spectrum Dual Nature

Electromagnetic Waves Waves of oscillating electric and magnetic fields Travel in a straight line unless . . . . .

Electromagnetic Waves they reflect, they refract, or they are diffracted.

Bell Work: Dual Nature Light can act like a _____ or a _____. A particle of light is called a _____. When talking about light, you are talking about all _____ parts of the EM spectrum. Which part of the EM spectrum has the highest frequency? Which part of the EM spectrum has the most energy?

Electromagnetic Particles Created in small packets called photons. Photons are released from atoms when electrons give off energy (b). Photons are absorbed when they run into an electron (a).

Electromagnetic Particles Travel at the speed of light unless . . . . . . . . they are absorbed when they run into an electron . . . . Then they travel at the speed of light until it all happens again . . . .absorbed. . . . emitted . . . . So, electromagnetic waves appear to move slower when they travel through matter. . . . . . .and reemitted from the atom.

Electromagnetic Spectrum Practice Problem Answers: 242 m and 3.08 m 0.122 m 19,700 s 4.07 x 1016 m 3.80 x 10-7 m 3 x 1014 Hz f = 5.4 x 1014 Hz 0.3 m 3.84 x 108 m 6.30 x 10-14 m

Visible Light Spectrum Red Orange Yellow Green Blue Violet RED GREEN BLUE ** primary light colors ** ** 1/3 of white light **

** secondary light colors ** RED GREEN BLUE YELLOW CYAN MAGENTA ** secondary light colors ** ** 2/3 of white light **

** absorb 1/3 of white light ** PIGMENTS ** primary pigments ** ** absorb 1/3 of white light ** **reflect other colors – that’s what you see**

Cyan Absorbs Red MAGENTA Yellow Absorbs Absorbs Green Blue Blue Green and Red Green Absorbs Blue and Red RED Absorbs Blue & Green

* secondary light colors * * absorb 2/3’s of white light * *reflect other color – that’s what you See*