Definition of quantum number

1.   1)  n is the principal quantum number.  n has possible values of 1,2,3...  2)  l is the orbital quantum number, having values of 0....n-1  3)  ml is the magnetic quantum number, having values of -l, -l+1....l  4)  ms is the spin quantum number, having a value of either 1/2 or -1/2. Definition for  Quantum Numbers :Numbers that describe the energies of electrons in atoms; derived from quantum mechanical treatment.