electron spin?

Question

i asked this in chemistry and got no answer, so ill ask it here.

according to my chemistry teacher 2 electrons in an orbital have to have opposite spins, so one is +1/2, the other is -1/2. but electrons are leptons, which all have -1/2 spin. so how does the spin of an electron change if its supposed to be -1/2.

Answer 1

Leptons all have a spin with magnitude 1/2. That spin can have a projection that is either "up" or "down" relative to some arbitrary axis. Some texts say +1/2 and -1/2 rather than up or down.