write out the electron configurations for each of the metallic ions:

Question

1. Ba^2+
2. Cu^2+
3. Li^+
4. K^+
5. Sr^2+
6. Ca^2+
7. Na^+

Answer 1

with those charges, the ions have lost the valence electrons, so the electron configuration is the same as the Noble Gas configuration in the previous period.

Answer 2

then whats the electron configuration in the Noble Gas configuration in the previous period ?