Question
The quantum numbers $$ + \frac{1}{2}$$ and $$ - \frac{1}{2}$$ for the electron spin
represent
A.
rotation of the electron in clockwise and anticlockwise direction respectively
B.
rotation of the electron in anticlockwise and clockwise direction respectively
C.
magnetic moment of the electron pointing up and down respectively
D.
two quantum mechanical spin states which have no classical analogue
Answer :
two quantum mechanical spin states which have no classical analogue
Solution :
The term spin implies that this magnetic moment is produced by the electron charge as the electron rotates about its own axis. Although this conveys a vivid mental picture of the source of the magnetism, the electron is not an extended body and its rotation is meaningless. Electron spin has no classical counterpart; the magnetic moment is a consequence of relativistic shifts in local space and time due to the high effective velocity of the electron in the atom.