# How can I solve a problem like this, “what is the eletronic distribution of Iron in layers”

What is the eletronic distribution in layers of Fe?

a) 2 – 8 – 10 – 2.
b) 2 – 8 – 12.
c) 2 – 8 – 8 – 4.
d) 2 – 8 – 18 – 18 – 8 – 2.
e) 2 – 8 – 14 – 2.


What is the approach to aswers this question? I can draw Linus Pauling diagram by heart. I also know that each layer has a number of electrons it can suppor k = 2, L = 8 and etc. With my knowledge I cannot solve this question. My answer would be like this, "because the atomic number of iron is 26 it would be 2-8-8-8. But this isn't an available choice.

If a use the Linux Pauling diagram I get an answer if use the rules of distribution I get another answer.

• No ! It is $2 - 8 - 14 - 2$. Reason : K, L, M, and N layers have a maximum number of electrons equal to $2, 8, 18, 32$. But when the $18$ first electrons are placed $2-8-8$, there is still ten places on the M layer. These $10$ electrons cannot be simply added on this layer without having started 2 electrons on the next N layer. So $2$ electrons are placed on the N layer. This allows to complete the M layer, adding the remaining electrons, which are 8. This reasoning is valid for people like you who do not know the structure s-p-d-f. Sorry for the reader who knows this structure. – Maurice Dec 13 '20 at 18:01