Spacial distance of paired electrons

[anorred]

Are paired electrons at a spatial distance from one another or are they "mixed" in some way. Why do their magnetic poles cancel?

 

[Drakkith]

They are mixed within their subshells. The pauli exclusion principle states that the electrons can never be in the same quantum state at the same time. Since quantum spin is one of the variables that determines the state of the electron, and has a value of +1/2 or -1/2 (up or down), two electrons can occupy the same subshell at the same time as long as they have opposite spins. (So in effect they would be in the same place at the same time but with opposite spins) The direction of spin is also the direction of the magnetic field, so the two electrons cancel each other out.

 

[sophiecentaur]

The direction of spin is also the direction of the magnetic field, so the two electrons cancel each other out.

I could ask why the axes of the two electrons would need to be 'aligned'. I know that's just being difficult but it has to be realized that we're in the quantum world and, until you start to measure the actual direction of the alignment in some way, it's totally uncommitted. Then +1/2 electron 'forces' the -1/2 spin electron to be in opposition.