Iodine would have a standard electron configuration of
The noble gas in the row above iodine is krypton.
We can replace
I hope this was helpful.
The full electron structure of iodine is :
The noble gas Krypton has the electron configuration:
We refer to this as the "Noble Gas Core" which we can write as :
So now we can write the electron configuration as :
You will note that iodine has 7 valence electrons in the outermost n = 5 energy level,