Hello; My physics teacher told me that there was a way to calculate the ionic charge of a transition metal given its electronic configuration, but he did not tell me how, because it is 'too complicated'. I can't find any useful webpages on the subject, either... my teacher said that the subject was "too A-level" and that I don't need to know... I will use an example. We can figure out that iron has an electronic configuration of 1s22s22p63s23p63d8. However, it has an ionic charge of 2+ (and sometimes 3+... why can it be either?). My question is, given this piece of information, how can one calculate iron's ionic charge? Or do you need more information? Thanks.