Statement - I :Cu⁺ is highly stable in aqueous solution.
Statement - II :E.C of Cu+ is [Ar]4s¹3d⁹.

In aqueous medium, Cu⁺² is more stable than Cu⁺. This is because although energy is required to remove one electron from Cu⁺ to Cu²⁺, high hydration energy of Cu²⁺ compensates for it. Therefore, Cu⁺ ion in an aqueous solution is unstable.

E.C of Cu⁺¹ is  [Ar]4s⁰3d¹⁰.