Question

EA, of Cu is -- 123 kJ mol-' whereas EA, of Zn is +87 kJ
mol- Explain​

Answer 1

There is a difference in EA values of Cu and Zn due to the difference in their electronic configuration

Explanation: In case of Cu

Cu [Ar]3d104s1 + 1e--- Cu[Ar]3d104s2

Here, the added electron goes into the empty orbital of 4s where it can face repulsion to a certain extent giving a positive value of EA that is 123 kJ mol-1.

In case of Zn [Ar]3d104s2 , when one electron is added to it , the electron accomodates into 4p orbital .Hence, giving negative value of EA that is -87kJmol-1.