Which electron is first ionized $n=2,\ell=1, m=?$ Eletrons in atoms are described by n,l, m, s quantum numbers?
For noble gas 1s2 2s2 2p6 which is the first electron that will be ionized n=2, l=1, m=?, s = ?
 A: Although it's convenient to think of individual electrons as being confined to individual atomic orbitals this isn't really true. If you could someone watch one particular electron you wouldn't see it stuck in just one orbital. All the electrons occupy all the orbitals.
If you look at  neon atom then you see a nucleus surrounded by a cloud of electrons. Those electrons are all delocalised, that is they don't have a position. All the electrons are spread out over the atom. We can conveniently describe the shape of the electron cloud as a sum of atomic orbitals, each of which on average contains two electrons. But this doesn't mean electrons are actually confined two to an orbital.
The point of this is that asking which atomic orbital the ejected electron came from doesn't really make sense because the electrons aren't confined to any one orbital. However what we can do is look at the atom after it has been ionised, break its electron density down to a sum of atomic orbitals and see how the ion differs from the atom.
If we do this we will find that the $1s$ and $2s$ orbitals each contain on average 2 electrons, and we will find that the $2p_x$, $2p_y$ and $2p_z$ orbitals each contain on average $\tfrac{5}{3}$ electrons. So we might argue that the electron came from the $2p$ orbitals, but we couldn't say from which one of the three $2p$ orbitals it came from.
As for the spin, all we can say is that the spin of the ejected electron and the electron spin of the ion will be opposite. In principle both the ejected electron and the ion are left in a superposition of spin states and will remain so until some interaction collapses  their wavefunction.
Later:
Amin makes a good point in a comment. In my answer I talk about looking at the ion after ejection of the electron and splitting up the electron density into a sum of atomic orbitals. My answer assumes that the ion has had time to settle down into its ground state. However if you use a very high energy photon then immediately after ejection of the electron the ion will be left in an excited state.
For example the Neon K edge is at 874eV. If we use a photon of this energy or above then analyse the electron distribution immediately after ionisation we'd find the $1s$ orbital contained on average 1 electron and all the other orbitals contained on average 2 electrons.
I suppose you could argue that the ejected electron came from $1s$ orbital, and perhaps I'm being a bit pedantic to insist otherwise. Nevertheless my point remains. The ejected electron wasn't confined to the $1s$ orbital before ionisation. Like all the electrons it was spread out over all the orbitals.
