The following table gives the electron affinities, in kJ/mol, for the group 1B and group 2B metals.
Why do the electron affinities of the group 1B elements become more negative as we move down the group? [Hint: Examine the trends in the electron affinity of other groups as we proceed down the periodic table.]
| Cu -119 | Zn >0 |
| Ag -126 | Cd >0 |
| Au -223 | Hg >0 |