Then this is the proper electron configuration. So ions also can be represented using electron configuration. For example, let's look at sodium plus has eleven protons and ten elections. So in order to write the electric configuration for this guy, we simply take away one electron from the highest energy level. So in this case, it would be one S, two two S, two two P, six. And we took out one electron from the three S, one orbital, so that that guy disappeared.