Why does the copper(I) ion Cu+ have 10 3d electrons?

1. list three scientific reasons cockroaches may fly.

Can someone me with 3 and 4 plz. this is for masteries test.

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!