ground-state electron configuration of a neutral atom of iron
Electron configurations of the elements (data page)
4s2
4p6
4d5

5s2

















2
8
18
13
2






44 Ru ruthenium : [Kr] 4d7 5s1


1s2
2s2
2p6
3s2
3p6
3d10
4s2
4p6
4d7

5s1

















2
8
18
15