Explore Atomic Orbitals 7

How Many Orbitals?

We have seen a substantial collection of orbitals so far. All of these different orbitals are grouped into subshells, labelled s, p, d or f, depending on what type of orbitals it contains:

Subshell	Number of Orbitals	Number of Nodal Planes	Total Number of Electrons
s	1	0	2
p	3	1	6
d	5	2	10
f	7	3	14
g	9	4	18

The subshells are grouped into shells, which correspond to the shells as described in the Bohr model of the atom. The number of subshells contained in each shell is noted to be equal to the number of the shell itself:

Shell (Old Name)	Shell (New Name)	Number of Subshells	List of Subshells
K	1	1	s
L	2	2	s, p
M	3	3	s, p, d
N	4	4	s, p, d, f
O	5	5	s, p, d, f, g

To distinguish a subshell in one shell from the same subshell in a different subshell, we label them with the shells' number. Thus the p subshell in shell 3 is known as 3p. One important fact that can be mentioned here is that orbitals in higher-numbered shells are larger than corresponding orbitals from lower-numbered shells. That is, although both 2p and 3p orbitals are "single dumbbells", the 3p orbitals a a bit bigger than the 2p orbitals.

So finally, a fairly complete "picture" of the orbitals available to electrons in an atom is as follows:

Shell	Orbitals
1	1s
2	2s	2p	2p	2p
3	3s	3p	3p	3p	3d	3d	3d	3d	3d
4	4s	4p	4p	4p	4d	4d	4d	4d	4d	4f	4f	4f	4f	4f	4f	4f
5	5s	5p	5p	5p	5d	5d	5d	5d	5d	5f	5f	5f	5f	5f	5f	…

Note that each of the white boxes above can hold at most two electrons. We can compress this picture by listing subshells instead of individual orbitals:

Shell	Subshells
1	1s
2	2s	2p
3	3s	3p	3d
4	4s	4p	4d	4f
5	5s	5p	5d	5f	5g
6	6s	6p	6d	6f	…
Electrons:	2	6	10	14	18

• Take a detour to Quantum Numbers.
• Take a detour to Radial Nodes.
• Continue with Explore Atomic Orbitals.