# Is it true that for a value of #n# (n-principal quantum number), the value of #m_l# (#m_l#-magnetic quantum number) is equal to #n^2#? If it is true, can you please explain this to me? Thanks.

##### 1 Answer

The *actual* value, no. The *number of values*, yes.

#### Explanation:

The relationship between the *principal quantum number*, *magnetic quantum number*, *angular momentum quantum number*,

The angular momentum quantum number can take any value that ranges from

The magnetic quantum number can take any value that ranges from

If you take into account the possible values of

So, for example, if

and

As you can see, the *individual values* of

However, the *total number of values*

The magnetic quantum number actually tells you how many orbitals a *subshell* has. In the above example, if

*2s-orbital*;

*three 3p-orbitals*.

This means that the second energy level has a total of two subshells, the 2s-subshell and the 2p-subshell.

The number of orbitals each subshell contains is given by

The 2p-subshell contains 3 orbitals, each denoted by a different value of

The total number of orbitals in the second energy level is **4**, which is equal to

If you try this with

*one 3s-orbital*;*three 3p-orbitals*;*five 3d-orbitals*.