Electron Spin

[Will Harvey 1B]

I understand that there are two directions (clockwise and counter-clockwise) that electrons can spin. However, I never really understood why they can only spin in two ways. Why are +1/2 and -1/2 the only options for electron spin?

[Carlotta Gherardi 2J]

Hi,

I'm not exactly sure but I believe it has to do with the fact that, due to the magnetic fields, the electrons cannot act like "spinning balls" (to quote the textbook), in the sense that the axis of spin cannot point any direction, it remains fixed in one direction, and on that axis the electrons can only either spin right or left, so clockwise or counterclockwise.

Hope this helps!

[Michael 1G]

According to the Pauli Exclusion Principle, there can be a maximum of 2 electrons for every orientation but those two electrons have to be spinning in different directions, which happen to be either clockwise or counterclockwise because of the previously mentioned magnetic fields.

[605607825]

According to the Pauli Exclusion Principle electrons in the same subshell have a parallel spin and are within different orbitals. Hund's Rule tells us that paired electrons cannot have the same spin but rather an opposite spin. If they are not organized in the same pair, they can have the same spin! I hope this helps!