Im not quite understanding the concept of electron configuration.
Cu+ is a transition metal which means it loses its highest n value since it is +
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d ^ 9 or
[Ar] 4s^2 3d^9
since its losing its highest n value it will be [Ar] 4s^1 3d^9
However, the answer is [Ar] 3d^10
can someone explain why?