Element x reacts with copper to form the compounds cux and cux2. in which group on the periodic table is element x found?

I think will be some halogen
Cu can have ions Cu+, Cu++, Cu+++
with halogens
CuCl
CuCl2
CuCl3
I am not sure if the  CuCl3 can exist as a compound
I saw some copper(III) oxide 
with elements from the group of Oxygen will form 
Cu2O
CuO
Cu2O3
doesn't fit with your experiment problem 
and with nitrogen 
Cu3N
Cu3N2
CuN
doesn't fit with your experiment either

I know the SEM (scanning electron microscope) lets you see objects in 3D