Superman and b159510:
Jsorex was the one with the "correctest" explanation so far, I think - although he did not exactly hit the nail on its head - but at least he used the hammer "quantum number = sum of electron states" - the right kind of tool...
Quantum numbers distinguish between particles and their states (note the plural!). Besides quantum numbers depicting common quantities like spin
s or charge
Q, there are also a few others:
Angular track momentum
LIsospin
ICharm
cOverall spin
Jz-component of the isospin
I3Strangeness
Sz-component of the spin
Szbaryon number
Bhyper charge
Hlepton number
LAccording to Pauli, the electronic states of a single atom must only be occupied in a way that allows for not more than 2 electrons to correlate in all quantum numbers. This implicates that for example with helium, one electron has to have an up-spin (s=+1/2) while the other must have a down-spin (s=-1/2).
Particles (read: electrons too) can only take on an angular momentum of
n/2 * h_ = h/2pi (h = Planck quantum effect number
(?translation?)).
So the smallest spin unit is x*
h_/2 (with x=1), and the number representing the factor x is called the quantum number in this case.
To indicate the spin of a particle, it therefore suffices to give the factor with which
h_ has to be multiplied to give the spin.
This number is also called the quantum spin number s.
There are particles with fermionic spin (numbered h/2, 3h/2, 5h/2 etc.) and bosonic spin (numbered 0, h, 2h, 3h etc.).
Other quantum numbers are numbered like this, for example: charge Q is either a multiple of the elemental charge
e or 1/3rd of it, the maximum value of the isospin I is n/2-1/2 with n being the number of particles forming a theoretical nucleon (i.e. neutron and proton, where n=2); the hyper charge H is calculated from charge Q and isospin I
3 according to the formula Y = 2(Q - I
3) (i.e. proton and neutron have the same hyper charge!) - strangeness S and charm C are quantum numbers solely used for differentiating between quarks...
Hope this helps.
(Superman: you maybe could've used GOOGLE to read about it: search for "quantum number pauli principle"
...
b159510: of course I'm a bit disappointed, because of your nickname, and, well - you know what I mean...
)
...and to complete your confusion: the quantum number of a complex particle is the sum of its modules quantum numbers.
(And of course quantum numbers just depict particle states that can only be described in portions or quantums - not necessarily just their detention probability/orbital shape, but also track angular momentum I, being quantified into the quantum numbers 1,2,3,4,5 etc. (being correspondant to S,P,D,F,G,H etc)...
)
indole_amine