Shapes and
Orientations of
Orbitals
Periodic table arrangement
s (n)
d (n - 1)
p (n)
1
2
3
4
5
6
7
f (n -2)
• the quantum theory helps to explain the
structure of the periodic table.
• n - 1 indicates that the d subshell in period 4
actually starts at 3 (4 - 1 = 3).
• The location of electrons is described by:
n, l, ml
n = size, l = shape, ml = orientation
Electron clouds
• The “probability” of finding an electron
around a nucleus can be calculated.
• Relative probability is indicated by a series
of dots, indicating the “electron cloud”.
• 90% electron probability/cloud
for 1s orbital (notice higher
probability toward the centre)
p orbitals and d orbitals
p orbitals look like
a dumbell with 3
orientations: px,
py, pz (“p sub z”).
Four of the d orbitals resemble two dumbells in a
clover shape. The last d orbital resembles a p
orbital with a donut wrapped around the middle.
n
1
l
0(s)
ml
0
2
0(s)
1(p)
3
0(s)
1(p)
2(d)
0
-1, 0, 1
0
-1, 0, 1
-2,-1, 0,1, 2
0
4
0(s)
ms
E
N
E
R
G
Y
3d
4s
3p
3s
2p
2s
1s
Movie: periodic table of the elements: t10-20