Question

What does a set of four quantum numbers tell you about an electron? Compare and contrast the locations and properties of two electrons with quantum number sets (4, 3, 1, +½) and (4, 3, -1, +½).

Answer 1

first: main quantum number n tells main energy level K,L,M,N, n = 1,2,3,4

second: side quantum number l tells suborbital s,p,d,f for s-orbital l = 0, p-orbital l = 1, values for it: l = 0, ... n-1

third is a magnetic quantum number, which can hace values from -l .. .0 ... l
e.g. l = 2 for d-orbital , m can have values -2, -1, 0, 1,2


It is related to case an atom is in magnetic field. Normally p-, d- and f-orbitals
have same energy. In a magnetic field orbitals split into different energy levels.

m = -2 is lowest, m = 2 is highest

spin quantum number s = - ½ or +½, because Electron is a charged partice, it has a magnetic moment.

Hund's rule says p- d- and f-orbitals are filled first with one electron with similar spin.

So, Electron, which has a set (4,3, -1, ½) is located N main energy level and d-suborbital, magnetic quantum number is 1 and spin ½. Later one describes an Electron which have magnetic quantum number -1, it has lower energy if an atom is out in a magnetic field.