The magnetic quantum number (ml
) has integer values between -l
and l, including zero. Thus for a certain value of l, there are (2l +1)
integer values of ml
as follows:
-l, (-l+1) . . ., –1, 0, 1, . . . (+l - 1), +l
These values describe the orientation of the orbital in space relative
to the other orbitals in the atom.
When l = 0, (2l+ 1) = 1 and there is only one value of ml
, thus we
have only one orbital i.e., 1s.
When l= 1, (2l+ 1) = 3, that means ml has three values, namely, -1,
0, and 1 or three p orbitals, with different orientations along x, y, z axes.
These are labelled as px, py, and pz
.• Do these three p-orbitals have the same
energy?
The number of ‘ml’ values indicates the number of orbitals in a sub-shell with a particular l value. Orbitals in the sub-shell belonging to
the same shell possess same energy. These are called degenerated orbitals.
Fill the table-1 with the number of
degenerated orbitals per sub-shell using (2l+1)
rule. s-orbital is spherical in shape, p-orbital is dumbell-shaped and
d-orbital are double dumbell-shaped as shown below
These are labelled as px, py, and pz