Chemistry Reference
In-Depth Information
z
z
z
z
y
y
y
x
x
x
x
1
s
orbital
(a)
d
xz
orbital
d
xy
orbital
d
yz
orbital
z
z
y
y
x
x
z
z
z
y
y
y
x
x
x
d
z
2
orbital
(c)
d
x
2
y
2
orbital
2
p
z
orbital
2
p
x
orbital
(b)
2
p
y
orbital
Figure 4.8
Shapes of Orbitals
(a) The 1
s
orbital.
(b) The three 2
p
orbitals.
(c) The five 3
d
orbitals.
A. (a) Along what axis does the orbital lie? (b) Along what axis does the
orbital lie? (c) Along what axes does the
p
y
orbital lie?
d
z
2
d
x
2
y
2
4.7
Energy Level Diagrams
Energy level diagrams
are models for portraying electrons' occupancy of an
atom's orbitals. They help chemists predict how many electrons occupy each
orbital of a subshell. Electron occupancy of the individual orbitals is important
in determining an atom's magnetic properties. A line or a box or a circle is used
to represent each orbital. An energy level diagram that could hold the electrons
of any known atom is shown in Figure 4.9. The energy level diagram is like a
graph in one dimension: The higher a subshell is placed, the higher the energy
of that subshell. The lines are spaced horizontally from left to right only to
prevent crowding so that the diagram is easier to read.
The lowest line on the energy level diagram represents the orbital in the 1
s
subshell of the atom. Much higher in the diagram, indicating a much higher
Figure 4.9
Energy level
6
f
7
p
Diagram
(not drawn to scale)
6
d
5
f
7
s
6
p
5
d
4
f
6
s
5
p
4
d
5
s
4
p
3
d
4
s
3
p
3
s
2
p
2
s
1
s
