Predict the ground-state electron configuration of each ion. Use the abbreviated noble gas notation.
Cu²+
Co³ +

I got answers of:

Cu - [Ar]4s^2 3d^7 ; [Ar]3d^7 ; [Ar]3d^10 ; [Ar]4s^1 3d^10

Co - [Ar]4s^2 3d^4 ; [Ar]3d^4

And these were all wrong, please help