Show that both the symmetric wave function Ws and the antisymmetric wave function WA of Eqs. (4.12) and (4.13), respectively, will yield probability density functions that are not in any way affected by the labeling of the two electrons.
Only clue from the book is below: We write a symmetric wave function s for the two-electron system as
WT+T,]
(4.12)
and an antisymmetric wave function A for the two-electron system as
(4.13)
If s is used in place of t to calculate the probability density function |s|^2, the result will be independent of the choice of the subscripts. In addition, since both T1 and T2 are valid solutions to Schrodinger's equation (Eq. (4.8)) and since s is a linear combination of these solutions, it follows that s is also a valid solution. The same argument applies to A (see Problem 4.20).