Lecture
#8 |
Text: Section 12.15 |
CURMUDGEON
GENERAL'S WARNING. These "slides"
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|
Lecture Outline |
The Periodic Table (continued)
Ionization energies
Second and third ionization energies
Electron affinity
|
The energy needed to remove the easiest-to-remove
electron from a neutral atom is called the first
ionization energy. |
![](GIF97_1/IE.01.GIF) |
First ionization energies for light elements. Using
this information, we can estimate the effective nuclear
charge, Zeff, for the electron being removed.
Helium as an example. |
![](GIF97_1/IE.02.GIF) |
Zeff for lithium |
![](GIF97_1/IE.03.GIF) |
Zeff for neon |
![](GIF97_1/IE.04.GIF) |
The detailed trend in ionization energies for the
light elements |
![](GIF2/IE.06.GIF) |
The n=1 shell filling |
![](GIF2/IE.07.GIF) |
The n=2 shell filling after which the n=3 shell
starts |
![](GIF2/IE.08.GIF) |
Starting the p-subshell causes a break in the smooth
trend across the row. |
![](GIF2/IE.09.GIF) |
Starting to pair up electrons after half the
p-subshell is filled causes a second break, which we
referred to as the mid-shell dip, in the smooth trend
across the row. |
![](GIF2/IE.10.GIF) |
First ionization energies across rows 1 through 3 of
the Periodic Table |
![](GIF2/IE.11.GIF) |
Overlapping the 2nd and 3rd row element first
ionization energies to demonstrate the repeating pattern
(determined by valence electron configuration) |
![](GIF2/IE.12.GIF) |
Second ionization energies |
![](GIF97_1/IE.13.GIF) |
First, second, and third ionization energies for the
light elements |
![](GIF2/IE.14.GIF) |
First, second, and third ionization energies shifted
to show, again, that valence electron configuration is
the determining driver |
![](GIF97_2/IE.15.GIF) |
Electron affinity is the energy involved in
adding an electron to a neutral atom to form a negative
ion. It is numerically equal to minus the ionization
energy for that negative ion. As such, we should expect
that the electron affinities also depend on electron
configuration. |
![](GIF97_1/EA.01.GIF) |