# How to write electron configuration of Mercury? [duplicate]

I am completely confused about how to write the electron configuration anything higher than Barium because there are so many inconsistencies and misconceptions about the 5d and 4f orbitals. I know that Lanthanum and Actinium have an outer orbital of d. Let's say I needed to write the configuration of Mercury. Wouldn't it be 1s2 (blah blah blah) 5d10 4f14? Because they always want to get to the lowest energy level? However, apparently, the correct way of writing it is 4f14 5d10...

## marked as duplicate by ringo, Jan, bon, M.A.R., WildcatSep 30 '16 at 23:44

So Hg is $\ce{[Xe] 4f^{14} 5d^{10} 6s^2}$