[Winga]

Why 'spin-orbit coupling' & 'exchange' make half-filled & full-filled orbitals extra stable?

[ssssss]

Why 'spin-orbit coupling' & 'exchange' make half-filled & full-filled orbitals extra stable?

Exchange Energy spent by electron in transition  lowers Down the Electrons total Energy causing more stability.Spin orbit coupling makes Symmetry and symmetrical System are considered to be more Stable.And once again i would say Dont go detail in it or you will be confused,just know it as in General.

[Winga]

But how can an electron exchange in a s-orbital?

[ssssss]

But how can an electron exchange in a s-orbital?

There are S orbitals with one electrons because of some Exceptions.