Does the Mg+2 ion have the same electron configuration as neon?

1 Answer
Jan 13, 2015

Yes, the Mg2+ ion and the neutral neon atom are isoelectronic, which implies that they have the same number of electrons and, of course, the same electron configuration.

Magnesium has an atomic number of 12, which means its neutral atom has 12 electrons. The Mg2+ ion is formed when the neutral magnesium atom loses 2 electrons, which brings its total number of electrons to 10.

Neon, which has an atomic number of 10, also has 10 electrons, which is why the electron configurations for the Mg2+ and for the neutral Ne atom will be the same.

Ne:1s22s22p6

Mg2+:1s22s22p6

Using the noble gas shorthand notation will get

Mg:[Ne]3s2

Mg2+:[Ne]

For example, Mg2+ is isoelectronic with other ions as well, like O2, Na+, and Al3+, just to name a few.

More on the Mg2+ ion here:

http://socratic.org/questions/what-is-the-full-electron-configuration-for-mg2