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Unformatted text preview: e orbit to another by either emitting or
absorbing photons with specific frequencies. Thus:
• To move to a higher energy orbit (a greater value of n) an
electron must _absorb
_____________________energy.
• To move to a lower energy orbit (a lower value of n) an
electron must emit energy.
• The frequency of the absorbed
or emitted energy corresponds
exactly to the energy difference
between the orbits.
those two 20 10 05Sep13 Ground state Excited states Absorption and emission energy (cont) Clip
21 Absorption and emission energy (cont)
1 λ =R 1
m2  1
n2 m: shell the transition
is to (innershell)
higher We use the Rydberg
equation to identify
spectral lines n: shell the transition
is from (outershell) higher where n > m
R: Rydberg constant
1.097x102 nm1
or
3.29x1015 Hz Aside: c = λ · v 1
1
= R 2 − 2 λ
n
m
1 1 1 ν = Rc 2 − 2 n
m
22 11 05Sep13 n=1 to n=2>more
distance and need
more energy. as it
is close to the
nucleus,it requires
more force bcoz of
the attraction. Which requires greater energy, an
electron promoted from n=1 to n=2, or
an electron promoted from n=3 to n = 4?
n=1 to n=2
Which releases a photon with greater
frequency, an n = 5 to n = 4 transition or
an n = 3 to n = 2 transition? Α)
Α) ν=R(1/42 – 1/52)= 7.4x1013 Hz
vs Β)
Β) ν=R(1/22 – 1/32)= 4.6x1014 Hz Which releases a photon with greater
wavelength, an n = 5 to n = 4 transition
or an n = 3 to n = 2 transition?
Α)
Α) λ=c/ν= (3 x 108 m/s)/(7.4 x 1013 Hz)
•λ= 4.05x106 m or 4052 nm near infrared
Β)
Β) λ=c/ν= (3 x 108 m/s)/(4.6 x1014 Hz)
•λ= 6.56x107 m or 656 nm red light
23 12...
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This document was uploaded on 02/18/2014.
 Fall '14
 Atom, pH

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