Introduction
In pre-16 chemistry, students encounter the ions Fe2+ and Fe3+. No attempt is made to look at the electron configuration or to explain the existence of ions of the same element with different charges.
However, in post-16 chemistry, there is an opportunity to start exploring these ideas.
Why do transition metals have ions with different charges?
The energy of the 4s and 3d orbtials are similar and so it is energetically feasible to remove several electrons from the 4s and 3d orbtitals.
Why don't group 1 metals have ions with different charges?
In the case of group 1 metals, once the valence electron has been ionised, the next electron to be ionised is from a lower energy level.
In this section we take a closer look at iron and some of its compounds.
What is the electron configuration of Fe2+?
The electron configuration of Fe2+ is [Ar] 3d6.
What is the electron configuration of Fe3+?
The electron configuration of Fe3+ is [Ar] 3d5.