Ryan Morrison & Ally Gray
What are Quantum Numbers?
• Specify the properties of an atomic orbital.
• An orbital is where an atom keeps its electrons.
Each element on the periodic table has a different set of Quantum Numbers, like their own address.
The primary rule of quantum numbers is that no two elements can have the same set of numbers,
this principle is also known as the Pauli Exclusion Principle.
For example: Nitrogen Oxygen
n=2 l=1 m=1 s=+½ n=2 l=1 m=(-1) s=(- ½)
These two elements may have a very similar address but it is not the same.
n represents the number of the orbital.
•Whatever row the
element is in, is
the number you
place for ‘n’.
•This number tells us
the energy level and
shell that the electron
is found in.
The higher a value for n,
means a higher amount •The principal quantum number (n)
of energy and the further cannot be zero. The allowed values of
away it is from the n are therefore 1, 2, 3, 4, and so on.
l represents the subshell
There are 4 different sub shells, they are 0, 1, 2 or 3 & are all represented by letters.
s is the purple (considered as 0)
p is the green (considered as 1)
d is the yellow (considered as 2)
f is the blue (considered as 3)
This quantum number characterizes the
electrons angular momentum and
determines the shape of the orbit.
Its possible values for an electron depend
on the value of that electron's principal
If n = 1, the only If n = 2, the only
quantum numbers, ranging from 0 to n-1.
Because of these different possibilities, possible value for possible values for
shells (other than the first shell) include quantum number l quantum number l
subshells. These are designated as is 0 (s). are 0 & 1 (s & p)
s(where l=0), p (where l=1), d (where l=2),
and f (where l=3) If n = 3+, the possible values
for quantum number l are
m represents magnetism.
The m orbital corresponds with the l orbital (subshells). If the subshell was d, it would
be equal to saying that m is: -2 ≤ m ≤ 2 or if the shell was p it would be -1 < m > 1. The
value of m indicates the orientation of the electron's orbit within the subshell.
m can range from 0 to a positive or negative number depending on the subshell.
For each column periodic table, the
magnetism that would be your number
for m is constant . If you find that your
number is bigger than 3 or smaller than
-3, you are incorrect because L only
ranges from -3<m<-3.
Example: if l = 2 then your m values will be:
-2, -1, 0, 1, 2, repeated twice to fill the column.
s represents spin.
• Moves in a circular/spherical shape
• Contains either a positive or
• A positive spin means the electrons
spin clockwise. (+½)
• A negative spin means the electron
spins counter-clockwise. (- ½)
• The first half of each orbital is + ½
and the other half is – ½ .
m = -2
s = +1/2
s = +1/2
l=0 s = +1/2