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

2. Electron Energy and Light
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) or (s–1)
wavelength ()
frequency ()
If both waves move at the same speed, which has more energy?
 and  are inversely proportional

3. Electromagnetic SpectrumY G B I V
Electromagnetic Spectrum
Lowest Energy
Highest Energy
(higher ) (shorter )
All EM radiation travels at the same speed:
the speed of light (c), 3.00  108 m/s.

5. c =  E = h  ↔   ↔ E joules (J) (given on test)
(c) speed of light
= 3.00 x 108 m/s
(h) Planck’s constant
= 6.63 x 10–34 J s
higher n , _______ l
(inversely)
shorter
higher n , ______ E
(directly)
higher
Calculate energy (E) from frequency (n) or wavelength (l):
 ↔ 
 ↔ E

6. c = λn Sample Calculation 1:
Calculate the wavelength of the yellow light emitted by a sodium lamp if frequency of the radiation is 5.10 x 1014 Hz.
(3.00 x 108) = λ (5.10 x 1014)
(3.00 x 108) = λ
(5.10 x 1014)
λ = x 10–7 m

7. c = λn Sample Calculation 2:
Calculate the frequency of blue light with a wavelength of 6.05 x 10–7 m (or 605 nm).
(3.00 x 108) = (6.05 x 10–7) n
(3.00 x 108) = n
(6.05 x 10–7)
n = x 1014 s–1

8. E = hn Sample Calculation 3:
Calculate the energy of the yellow light emitted by a sodium lamp if frequency of the radiation is 5.10 x 1014 Hz.
E = (6.63 x 10–34) (5.10 x 1014)
E = x 10–19 J

9. c = λn E = hn Sample Calculation 4:
Calculate the energy of blue light with a wavelength (l) of 6.05 x 10–7 m (or 605 nm).
c = λn
(3.00 x 108) = (6.05 x 10–7) n
(3.00 x 108) = n
(6.05 x 10–7)
n = x 1014 s–1
E = hn
E = (6.63 x 10–34) (4.96 x 1014)
E = x 10–19 J

10. 1. Which of the following relationships is true?
Quick Quiz!
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.

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

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