vivtoons

What do you mean by homework question???it is a chemistry question.If you don't know the answer then simply say that you don't know.But at least don't make excuses.

My questions exactly are: Q 1: Why 3d10 4s1 configuration of copper is more stable than 3d9 4s2 in terms of exchange energy ? Q 2 : Can a electron of 3d exchange to 4s electron, having same spin? Q3: How many possible exchange sets with a parallel spins can occur in copper ? Please help me asap.