Why are there four quantum numbers?

1 Answer
Jul 6, 2017


Evidently, precisely four are needed to describe the probable location of an electron in an atom. To be sure, nature made it so.


#n#: the principal quantum number merely relates the size of the orbital
#l#: the angular quantum number relates the shape of the orbital
#m_l#: the magnetic quantum number relates the spatial orientation of orbital
#m_s#: the spin magnetic quantum number relates the direction of rotation of an electron

For instance, an electron with the quantum numbers:
#3p_x, -1/2#

is located in the third shell, the #p_x# subshell of said shell, and is spinning down.

What more could we need to know about the electron?