Answer:
The electron configuration for Iron (Fe) with 26 electrons is as follows 1s²2s²2p⁶3s²3p⁶4s²3d⁶ (the superscripts add up to 26) or the Noble gas [Ar] 4s²3d⁶
Explanation:
The subshells fill up in the order 1s, 2s,2p, 3s,3p,4s,3d... (etc) the subshells have the following number of e⁻ (electrons) s: 2, p:6, d:10, f:14. I attached the subshell levels and where to find them on the periodic table that I made when I taught this to myself after lecture. You can use the noble gas from the previous row to make this simpler to write.
