Transcript Quantum Numbers

Quantum Numbers
SCH12U
September 13 2011
Mr. Dvorsky
Introduction to
Quantum Numbers
• The location of electrons can be identified by its orbital
type. These names indicated the following about the
electron:
• Another system used to identify an electron is the
quantum number system. With this system a particular
electron is designated by a set of 4 numbers.
Principle Quantum Number,n
• This indicates the energy level of the electron
i.e. N = 1,2,3,4,5, etc.
-can have any integer value between 1 and
infinity.
Secondary Quantum
Number
• Indicates the type of orbital that the electron
is in.
l =0 (s orbital)
l = 1 (p orbital)
l = 2 (d orbital)
l = 3 (f orbital)
Magnetic Quantum
Number, ml or m
• This indicates the orientation of the orbital
that the electron is in. The possible values
depend on the value for l.
When l=0  ml = 0 (only 1 spherical orientation)
When l = 1  ml = +1 (px), ml = 0 (py), ml = -1 (pz)
When l = 2  ml = +2, +1, 0, -1, -2
When l = 3  ml = +3, +2, +1, 0, -1, -2, -3
Spin Quantum Number,
ms or s
• Each orbital can contain 2 electrons. However
these 2 electrons must have opposite spin.
These are the same for all orbitals.
• ms = + ½ and - ½
What are the possible quantum numbers of an electron in
the following orbitals:
a) 1s
b) 2px
c) 4d
n=1
n=2
n=4
l=0
ml = 0
l=1
ml = +1
l=2
ml = +2...0...-2
Note that no 2 electrons in an atom can have the same 4
quantum numbers.