Apparently there are two helicities or "handednesses" of an electron: right and left. A right-handed electron spins in the same direction as its phase advances, whereas the left-handed electron spins opposite to its phase advance. This leads to many questions in my mind, some of which this foum might be able to answer: 1) Do both types of electrons occur in equal numbers, or is there a preponderance of one over the other? 2) Is the helicity of an electron fixed for all time, or is it easily and frequently reversed? If it does reverse, what could cause this reversal? 3) Is it also true that the intrinsic magnetic moments of two electrons having the same spin but opposite helicities point in opposite directions? 4) Can two electrons having the same spin but opposite helicities exist in the same quantum state, or is helicity part of the electron's state? 5) How do we know that there are two helicities of electrons? What experiment confirms this? Thank you for any replies that might be forthcoming.