The element Cu with atomic number 29 undergoes chemical reaction to form an ion with oxidation number +2.
a) Write down the subshell electronic configuration of this ion?
b) Can this element show variable valency? Why?
c) Write down the chemical formula of one compound formed when this elemrnt reacts with chlorine `(Cl_17)`

Explanation

a)`Cu^2 - 1s^2 2s^2 2p^6 3s^2 3p^6 3d^9`
b) Yes, because Cu is a transition element .
c) `Cu^2+Cl^- rarr CuCl_2`