Is there any surefire way to recognize exceptions to normal electron configurations (like In3+ takes the 5s2 and 4d8, and makes it 4d10)? Do we always add or subtract like this in order to make full shells?

Question

Is there any surefire way to recognize exceptions to normal electron configurations (like In3+ takes the 5s2 and 4d8, and makes it 4d10)?  Do we always add or subtract like this in order to make full shells?

anonymous · Answer

I think it is whenever we can eliminate the second to last one while filling the last one.

anonymous · Answer

Unless there an f is involved as the second to last, then we use the 3rd to last to supplement the last, correct?

anonymous · Answer

We don't necessarily have to fill out the last one, just as much as it can, right?

aaronq · Answer

Once you ionize a molecule the electrons should be filled in order of increasing principal quantum number.

like if you have $Pd^{\;2+}$, it's electron configuration is $[Kr]4d^8$ and not $[Kr]5s^24d^6$

aaronq · Answer

ionize an atom******