What are the electronic configurations of common atomic ions?

1 Answer
Nov 8, 2016

Usually the electronic configuration is the same as that of the NEAREST inert gas.

Explanation:

Excluding the transition metals, the common ions of the 1st short rows are the same as that of the neutral inert gas. Consider the common ions of nitrogen, #N^(3-)#, #O^(2-)#, and #F^(-)#; all of these ions have 8 valence electrons, and a formal electronic configuration of #1s^(2)2s^(2)2p^6#. While these ions have negative charges, these are isolelectronic with #[Ne]#, the inert gas with 8 valence electrons.

#Na^+#, and #Mg^(2+)# in the same way have the same formal #[Ne]# configuration. Why?

How do you propose to represent #P^(3-)#, #S^(2-)#, and #Cl^-#?