Question

What are m and s for a `3p` electron?

Answer 1

Could you be referring to the quantum numbers `m_l` and `m_s`, corresponding maybe to the electrons in a 3p-orbital?

Let's assume you are talking about chlorine, which has an electron configuration

`"Cl": ["Ne"]3s^(2)3p^5`

and you want to determine the magnetic quantum number, `m_l`, and the spin quantum number, `m_s`, for the unpaired electron sitting in a 3p-orbital.

Since you are dealing with a 3p-orbital, your principal and angular momentum quantum numbers will be `n=3` and `l=1`.

The magnetic quantum number can only take integer values ranging from `-l` to `+l`, so you have three possible values for `m_l`:

`m_l =-1`, `m_l = 0`, and `m_l = +1`,

each corresponding to one of the three 3p-orbitals `3p_x`, `3p_y`, and `3p_z`. Let's ssume that

`"Cl": ["Ne"]3s^(2)3p_x^(2)3p_y^(2)3p_z^(1)`

In this case, the unpaired electron can be found in the `3p_z` orbital, which corresponds to `m_l = +1`.

Since the spin quantum number can only be `-1/2` or `+1/2`, and since no electrons are already present to influence the spin, let's assume your electron has a positive spin, `+1/2`.

So, the quantum numbers that describe chlorine' unpaired electron are:

`n=3`
`l=1`
`m_l = +1`
`m_s = +1/2`