1. Bohr’s Shell Model e – ’s emit (–) energy, move back to inner levels (n=5 to n=2) e – ’s absorb (+) energy, move to outer levels (n=2 to n=5) EXCITED state GROUND state ∆E 5 2 quantum:quantum: amount of energy absorbed or emitted as electrons transition fixed energy levels.

2. The distance between same points on adjacent waves is the _______________. (m) The number of waves passing a point per unit of time is the ______________. (Hz)(s –1 )  and are inversely proportional wavelength ( ) frequency ( ) If both waves move at the same speed, which has more energy? Electron Energy and Light

3. All EM radiation travels at the same speed: the speed of light (c), 3.00  10 8 m/s. ROYGBIV (higher ) (shorter ) Lowest EnergyHighest Energy Electromagnetic Spectrum

5. Calculate energy (E) from frequency ( ) or wavelength ( ): E = h c = (given on test)  ↔  ↔ E higher _______ (inversely) higher ______ E (directly) joules (J) (h) Planck’s constant = 6.63 x 10 –34 (c) speed of light = 3.00 x 10 8 m/s shorterhigher

6. Calculate the wavelength of the yellow light emitted by a sodium lamp if frequency of the radiation is 5.10 x 10 14 Hz. c = λ Sample Calculation 1: (3.00 x 10 8 ) = λ (5.10 x 10 14 ) (3.00 x 10 8 ) = λ (5.10 x 10 14 ) λ = 5.88 x 10 –7 m

7. Calculate the frequency of blue light with a wavelength of 6.05 x 10 –7 m (or 605 nm). Sample Calculation 2: c = λ (3.00 x 10 8 ) = (6.05 x 10 –7 ) (3.00 x 10 8 ) = (6.05 x 10 –7 ) = 4.96 x 10 14 s –1

8. Calculate the energy of the yellow light emitted by a sodium lamp if frequency of the radiation is 5.10 x 10 14 Hz. Sample Calculation 3: E = h E = (6.63 x 10 –34 ) (5.10 x 10 14 ) E = 3.38 x 10 –19 J

9. Calculate the energy of blue light with a wavelength ( ) of 6.05 x 10 –7 m (or 605 nm). Sample Calculation 4: E = h c = λ (3.00 x 10 8 ) = (6.05 x 10 –7 ) (3.00 x 10 8 ) = (6.05 x 10 –7 ) = 4.96 x 10 14 s –1 E = (6.63 x 10 –34 ) (4.96 x 10 14 ) E = 3.29 x 10 –19 J E = h c = λ

10. 1.Which of the following relationships is true? A.Higher-energy light has a higher frequency than lower-energy light. B.Higher-energy light has a longer wavelength than lower-energy light. C.Higher-energy light travels at a faster speed than lower-energy light. D.Higher-frequency light travels at a slower speed than lower-energy light does. Quick Quiz!

11. 2. The energy of EM radiation is greatest for… A.visible light. B.ultraviolet light. C.infrared light. D.X-ray radiation. Quick Quiz.

12. 3. The longer the wavelength of light, the… A.higher the frequency. B.higher the energy. C.lower the frequency. D.lower the energy. Quick Quiz.