• Electron configuration of Ds

Question related to mission Periodic Table

 

While Googling to pass checkio("Ds"), I came across two different electron configurations of Ds.

One is "[Rn] 5f¹⁴6d⁸7s²" (http://en.wikipedia.org/wiki/Darmstadtium), and the other is "[Rn] 5f¹⁴6d⁹7s¹" (http://www.rsc.org/periodic-table/element/110/darmstadtium).

Is either outdated? Or are both correct?