South Pasadena • AP Chemistry
Name
8 ▪ Atomic Theory
Period
8.2
PROBLEMS
–
Date
ELECTRON CONFIGURATION
1. For each of the following elements, write: (i) its short form ground state electron configuration, (ii) the
number of valence electrons, (iii) the number of unpaired electrons, (iv) whether it’s paramagnetic or
diamagnetic, (v) its most likely ion(s), and (vi) the short form electron configuration of its most likely ion.
# Valence e− #Unpaired e−
Element
Electron Configuration
Para | Dia
Likely Ion(s)
Electron Configuration
Se
[Ar] 4s2 3d10 4p4
6
2
Para
Se2−
[Ar] 4s2 3d10 4p6
In
[Kr] 5s2 4d10 5p1
3
1
Para
In+
In3+
[Kr] 5s2 4d10
[Kr] 4d10
Ba
[Xe] 6s2
2
0
Dia
Ba2+
[Xe]
W
[Xe] 6s2 4f14 5d4
2
4
Para
W6+
[Xe] 4f14
Ag
exception
[Kr] 5s1 4d10
1
1
Para
Ag+
[Kr] 4d10
Cd
[Kr] 5s2 4d10
2
0
Dia
Cd2+
[Kr] 4d10
[Kr] 5s2 4d10
[Kr] 4d10
[Kr] 5s2 4d10
Sn
2
[Kr] 5s 4d 5p
4
2
Para
Sn2+
Sn4+
Xe
[Kr] 5s2 4d10 5p6
8
0
Dia
Xe6+
2
10
2. The PES spectrum for Mg is
shown. Sketch in the spectrum
for Al on the same axes.
3. The PES spectra of H,
He, Li, and Be are given.
Sketch in the spectrum
for B above the other
spectra.
25
20
15
10
Binding Energy (MJ/mol)
5
0
4. Label each of the following spectra using electron configuration notation
(1s2, 2s2, etc.) and determine the identity of each element.
2p
1s
2s
Ne
2p
1s
2s
F
2s2p
1s
O
1s
2p
2s
N
1s
C
2s
1s
2p
2s 2p
B
90
80
70
60
50
40
30
20
5
Binding Energy (MJ/mol)
5. Which of the following best explains the relative positioning and intensity of the 2s peaks in the following
spectra?
(A) Be has a greater nuclear charge than Li and more electrons in the 2s orbital
(B) Be electrons experience greater electron-electron repulsions than Li electrons
(C) Li has a greater pull from the nucleus on the 2s electrons, so they are harder to remove
(D) Li has greater electron shielding by the 1s orbital, so the 2s electrons are easier to remove
0